View source for Matrix with two diagonals

{{Draft task}}

;Task:
Draw a square matrix which has 1's on both diagonals but 0's elsewhere.
<br> If you can please use GUI
<br><br>

=={{header|Ada}}==
<lang Ada>with Ada.Text_Io; use Ada.Text_Io;
with Ada.Command_Line;

procedure Matrix_With_Diagonals is

   type Matrix_Type is array (Positive range <>, Positive range <>) of Character;

   function Matrix_X (Length : Natural) return Matrix_Type is
   begin
      return M : Matrix_Type (1 .. Length, 1 .. Length) do
         for Row in M'Range (1) loop
            for Col in M'Range (2) loop
               M (Row, Col) := (if
                                  Row = Col or else
                                  Row = M'Last (2) - (Col - M'First (1))
                                then '1' else '0');
            end loop;
         end loop;
      end return;
   end Matrix_X;

   procedure Put (M : Matrix_Type) is
   begin
      for Row in M'Range (1) loop
         for Col in M'Range (2) loop
            Put (' ');
            Put (M (Row, Col));
         end loop;
         New_Line;
      end loop;
   end Put;

begin
   Put (Matrix_X (Length => Natural'Value (Ada.Command_Line.Argument (1))));

exception
   when others =>
      Put_Line ("Usage: ./matrix_with_diagonals <side-length>");

end Matrix_With_Diagonals;</lang>

=={{header|ALGOL 68}}==
<lang algol68>BEGIN # draw a matrix with 1s on the diagonals and 0s elsewhere         #
    # draws a matrix with height and width = n with 1s on the diagonals #
    PROC draw 2 diagonals = ( INT n )VOID:
         BEGIN
            INT l pos := 1;
            INT r pos := n;
            FOR i TO n DO
                FOR j TO n DO
                    print( ( " ", whole( ABS ( j = l pos OR j = rpos ), 0 ) ) )
                OD;
                print( ( newline ) );
                l pos +:= 1;
                r pos -:= 1
            OD
         END # draw 2 diagonals # ;
    # test the draw 2 diagonals procedure #
    draw 2 diagonals( 10 );
    print( ( newline ) );
    draw 2 diagonals( 11 )
END</lang>
{{out}}
<pre>
 1 0 0 0 0 0 0 0 0 1
 0 1 0 0 0 0 0 0 1 0
 0 0 1 0 0 0 0 1 0 0
 0 0 0 1 0 0 1 0 0 0
 0 0 0 0 1 1 0 0 0 0
 0 0 0 0 1 1 0 0 0 0
 0 0 0 1 0 0 1 0 0 0
 0 0 1 0 0 0 0 1 0 0
 0 1 0 0 0 0 0 0 1 0
 1 0 0 0 0 0 0 0 0 1

 1 0 0 0 0 0 0 0 0 0 1
 0 1 0 0 0 0 0 0 0 1 0
 0 0 1 0 0 0 0 0 1 0 0
 0 0 0 1 0 0 0 1 0 0 0
 0 0 0 0 1 0 1 0 0 0 0
 0 0 0 0 0 1 0 0 0 0 0
 0 0 0 0 1 0 1 0 0 0 0
 0 0 0 1 0 0 0 1 0 0 0
 0 0 1 0 0 0 0 0 1 0 0
 0 1 0 0 0 0 0 0 0 1 0
 1 0 0 0 0 0 0 0 0 0 1
</pre>

=={{header|APL}}==
{{works with|Dyalog APL}}
<lang apl>twoDiagonals ← (⌽∨⊢)∘.=⍨∘⍳
twoDiagonals¨ 10 11</lang>
{{out}}
<pre> 1 0 0 0 0 0 0 0 0 1  1 0 0 0 0 0 0 0 0 0 1 
 0 1 0 0 0 0 0 0 1 0  0 1 0 0 0 0 0 0 0 1 0 
 0 0 1 0 0 0 0 1 0 0  0 0 1 0 0 0 0 0 1 0 0 
 0 0 0 1 0 0 1 0 0 0  0 0 0 1 0 0 0 1 0 0 0 
 0 0 0 0 1 1 0 0 0 0  0 0 0 0 1 0 1 0 0 0 0 
 0 0 0 0 1 1 0 0 0 0  0 0 0 0 0 1 0 0 0 0 0 
 0 0 0 1 0 0 1 0 0 0  0 0 0 0 1 0 1 0 0 0 0 
 0 0 1 0 0 0 0 1 0 0  0 0 0 1 0 0 0 1 0 0 0 
 0 1 0 0 0 0 0 0 1 0  0 0 1 0 0 0 0 0 1 0 0 
 1 0 0 0 0 0 0 0 0 1  0 1 0 0 0 0 0 0 0 1 0 
                      1 0 0 0 0 0 0 0 0 0 1 </pre>
=={{header|AppleScript}}==
===Procedural===
<lang applescript>on twoDiagonalMatrix(n)
    if (n < 2) then error "twoDiagonalMatrix() handler: parameter must be > 1."
    
    set digits to {}
    set oddness to n mod 2
    repeat (n - 1 + oddness) times
        set end of digits to 0
    end repeat
    set m to n div 2 + oddness -- Middle index of digit source list.
    set item m of digits to 1
    
    set matrix to {}
    set leftLen to m - 1 -- Length of left end of each row - 1.
    set rightLen to leftLen - oddness -- Length of right end ditto.
    -- Assemble the first m rows from the relevant sections of 'digits'.
    repeat with i from m to 1 by -1
        set end of matrix to items i thru (i + leftLen) of digits & items -(i + rightLen) thru -i of digits
    end repeat
    
    -- The remaining rows are the reverse of these, not repeating the mth where n is odd.
    return matrix & reverse of items 1 thru (m - oddness) of matrix
end twoDiagonalMatrix

-- Task code.
on matrixToText(matrix, separator)
    copy matrix to matrix
    set astid to AppleScript's text item delimiters
    set AppleScript's text item delimiters to separator
    repeat with thisLine in matrix
        set thisLine's contents to thisLine as text
    end repeat
    set AppleScript's text item delimiters to linefeed
    set matrix to matrix as text
    set AppleScript's text item delimiters to astid
    return matrix
end matrixToText

return linefeed & matrixToText(twoDiagonalMatrix(7), space) & ¬
    (linefeed & linefeed & matrixToText(twoDiagonalMatrix(8), space))</lang>

{{output}}
<lang applescript>"
1 0 0 0 0 0 1
0 1 0 0 0 1 0
0 0 1 0 1 0 0
0 0 0 1 0 0 0
0 0 1 0 1 0 0
0 1 0 0 0 1 0
1 0 0 0 0 0 1

1 0 0 0 0 0 0 1
0 1 0 0 0 0 1 0
0 0 1 0 0 1 0 0
0 0 0 1 1 0 0 0
0 0 0 1 1 0 0 0
0 0 1 0 0 1 0 0
0 1 0 0 0 0 1 0
1 0 0 0 0 0 0 1"</lang>

===Functional===
<lang applescript>---------------- MATRIX WITH TWO DIAGONALS ---------------

-- bothDiagonals :: Int -> [[Int]]
on bothDiagonals(n)
    -- A square matrix of dimension n with ones
    -- along both diagonals, and zeros elsewhere.
    script idOrReflection
        on |λ|(x, y)
            ({y, 1 + n - y} contains x) as integer
        end |λ|
    end script
    
    matrix(n, n, idOrReflection)
end bothDiagonals


--------------------------- TEST -------------------------
on run
    -- Two diagonal matrices of dimensions 7 and 8
    
    unlines(map(compose(showMatrix, bothDiagonals), ¬
        {7, 8}))
end run


------------------------- GENERIC ------------------------

-- compose (<<<) :: (b -> c) -> (a -> b) -> a -> c
on compose(f, g)
    script
        property mf : mReturn(f)
        property mg : mReturn(g)
        on |λ|(x)
            mf's |λ|(mg's |λ|(x))
        end |λ|
    end script
end compose


-- enumFromTo :: Int -> Int -> [Int]
on enumFromTo(m, n)
    if m ≤ n then
        set xs to {}
        repeat with i from m to n
            set end of xs to i
        end repeat
        xs
    else
        {}
    end if
end enumFromTo


-- matrix :: Int -> Int -> ((Int, Int) -> a) -> [[a]]
on matrix(nRows, nCols, f)
    -- A matrix of a given number of columns and rows,
    -- in which each value is a given function of its
    -- (zero-based) column and row indices.
    script go
        property g : mReturn(f)'s |λ|
        on |λ|(iRow)
            set xs to {}
            repeat with iCol from 1 to nCols
                set end of xs to g(iRow, iCol)
            end repeat
            xs
        end |λ|
    end script
    
    map(go, enumFromTo(1, nRows))
end matrix


-- map :: (a -> b) -> [a] -> [b]
on map(f, xs)
    -- The list obtained by applying f
    -- to each element of xs.
    tell mReturn(f)
        set lng to length of xs
        set lst to {}
        repeat with i from 1 to lng
            set end of lst to |λ|(item i of xs, i, xs)
        end repeat
        return lst
    end tell
end map


-- mReturn :: First-class m => (a -> b) -> m (a -> b)
on mReturn(f)
    -- 2nd class handler function lifted into 1st class script wrapper. 
    if script is class of f then
        f
    else
        script
            property |λ| : f
        end script
    end if
end mReturn


-- showMatrix :: [[a]] -> String
on showMatrix(rows)
    -- String representation of a matrix.
    script
        on |λ|(cells)
            unwords(map(my str, cells))
        end |λ|
    end script
    
    unlines(map(result, rows)) & linefeed
end showMatrix


-- str :: a -> String
on str(x)
    x as string
end str


-- unlines :: [String] -> String
on unlines(xs)
    -- A single string formed by the intercalation
    -- of a list of strings with the newline character.
    set {dlm, my text item delimiters} to ¬
        {my text item delimiters, linefeed}
    set s to xs as text
    set my text item delimiters to dlm
    s
end unlines


-- unwords :: [String] -> String
on unwords(xs)
    set {dlm, my text item delimiters} to ¬
        {my text item delimiters, space}
    set s to xs as text
    set my text item delimiters to dlm
    return s
end unwords</lang>
{{Out}}
<pre>1 0 0 0 0 0 1
0 1 0 0 0 1 0
0 0 1 0 1 0 0
0 0 0 1 0 0 0
0 0 1 0 1 0 0
0 1 0 0 0 1 0
1 0 0 0 0 0 1

1 0 0 0 0 0 0 1
0 1 0 0 0 0 1 0
0 0 1 0 0 1 0 0
0 0 0 1 1 0 0 0
0 0 0 1 1 0 0 0
0 0 1 0 0 1 0 0
0 1 0 0 0 0 1 0
1 0 0 0 0 0 0 1</pre>

=={{header|Arturo}}==

<lang rebol>drawSquare: function [side][
    loop 1..side 'x ->
        print map 1..side 'y [
            (any? @[x=y side=x+y-1])? -> 1 -> 0
        ]
]

drawSquare 6
print ""
drawSquare 9</lang>

{{out}}

<pre>1 0 0 0 0 1 
0 1 0 0 1 0 
0 0 1 1 0 0 
0 0 1 1 0 0 
0 1 0 0 1 0 
1 0 0 0 0 1 

1 0 0 0 0 0 0 0 1 
0 1 0 0 0 0 0 1 0 
0 0 1 0 0 0 1 0 0 
0 0 0 1 0 1 0 0 0 
0 0 0 0 1 0 0 0 0 
0 0 0 1 0 1 0 0 0 
0 0 1 0 0 0 1 0 0 
0 1 0 0 0 0 0 1 0 
1 0 0 0 0 0 0 0 1</pre>

=={{header|AWK}}==
<lang AWK>
# syntax: GAWK -f MATRIX_WITH_TWO_DIAGONALS.AWK
BEGIN {
    for (n=6; n<=7; n++) {
      for (i=1; i<=n; i++) {
        for (j=1; j<=n; j++) {
          tmp = (i==j || i+j==n+1) ? 1 : 0
          printf("%2d",tmp)
        }
        printf("\n")
      }
      print("")
    }
    exit(0)
}
</lang>
{{out}}
<pre>
 1 0 0 0 0 1
 0 1 0 0 1 0
 0 0 1 1 0 0
 0 0 1 1 0 0
 0 1 0 0 1 0
 1 0 0 0 0 1

 1 0 0 0 0 0 1
 0 1 0 0 0 1 0
 0 0 1 0 1 0 0
 0 0 0 1 0 0 0
 0 0 1 0 1 0 0
 0 1 0 0 0 1 0
 1 0 0 0 0 0 1
</pre>

=={{header|Basic}}==
<lang qbasic>100 REM
110 REM DIAGONAL-DIAGONAL MATRIX
120 REM
130 LET N = 7
140 DIM A(N,N)
150 FOR I=1 TO N
150 FOR J=1 TO N
160 LET A(I,J) = 0
170 NEXT J
180 LET J1 = I
190 LET J2 = N - I + 1
200 LET A(I,J1) = 1
210 LET A(I,J2) = 1
220 NEXT I
230 REM
240 FOR I=1 TO N
250 FOR J=1 TO N
260 PRINT " ";A(I,J);
270 NEXT J
280 PRINT
290 NEXT I
300 END
</lang>
{{Output}}
<pre> 1 0 0 0 0 0 1
 0 1 0 0 0 1 0
 0 0 1 0 1 0 0
 0 0 0 1 0 0 0
 0 0 1 0 1 0 0
 0 1 0 0 0 1 0
 1 0 0 0 0 0 1
</pre>

=={{header|BCPL}}==
<lang bcpl>get "libhdr"

let diagonals(size) be
    for y = 1 to size
        for x = 1 to size
            do writef("%C%C", 
                x=y | size-x=y-1 -> '1', '0',
                x=size -> '*N', ' ')
  
let start() be
$(  diagonals(9)
    wrch('*N')
    diagonals(10)
$)</lang>
{{out}}
<pre>1 0 0 0 0 0 0 0 1
0 1 0 0 0 0 0 1 0
0 0 1 0 0 0 1 0 0
0 0 0 1 0 1 0 0 0
0 0 0 0 1 0 0 0 0
0 0 0 1 0 1 0 0 0
0 0 1 0 0 0 1 0 0
0 1 0 0 0 0 0 1 0
1 0 0 0 0 0 0 0 1

1 0 0 0 0 0 0 0 0 1
0 1 0 0 0 0 0 0 1 0
0 0 1 0 0 0 0 1 0 0
0 0 0 1 0 0 1 0 0 0
0 0 0 0 1 1 0 0 0 0
0 0 0 0 1 1 0 0 0 0
0 0 0 1 0 0 1 0 0 0
0 0 1 0 0 0 0 1 0 0
0 1 0 0 0 0 0 0 1 0
1 0 0 0 0 0 0 0 0 1</pre>

=={{header|C}}==
{{trans|Wren}}
<lang c>#include <stdio.h>

void specialMatrix(unsigned int n) {
    int i, j;
    for (i = 0; i < n; ++i) {
        for (j = 0; j < n; ++j) {
            if (i == j || i + j == n - 1) {
                printf("%d ", 1);
            } else {
                printf("%d ", 0);
            }
        }
        printf("\n");
    }
}

int main() {
    specialMatrix(10); // even n
    printf("\n");
    specialMatrix(11); // odd n
    return 0;
}</lang>

{{out}}
<pre>
1 0 0 0 0 0 0 0 0 1 
0 1 0 0 0 0 0 0 1 0 
0 0 1 0 0 0 0 1 0 0 
0 0 0 1 0 0 1 0 0 0 
0 0 0 0 1 1 0 0 0 0 
0 0 0 0 1 1 0 0 0 0 
0 0 0 1 0 0 1 0 0 0 
0 0 1 0 0 0 0 1 0 0 
0 1 0 0 0 0 0 0 1 0 
1 0 0 0 0 0 0 0 0 1 

1 0 0 0 0 0 0 0 0 0 1 
0 1 0 0 0 0 0 0 0 1 0 
0 0 1 0 0 0 0 0 1 0 0 
0 0 0 1 0 0 0 1 0 0 0 
0 0 0 0 1 0 1 0 0 0 0 
0 0 0 0 0 1 0 0 0 0 0 
0 0 0 0 1 0 1 0 0 0 0 
0 0 0 1 0 0 0 1 0 0 0 
0 0 1 0 0 0 0 0 1 0 0 
0 1 0 0 0 0 0 0 0 1 0 
1 0 0 0 0 0 0 0 0 0 1 
</pre>

=={{header|C++}}==
<lang cpp>#include <concepts>
#include <iostream>

// Print each element of a matrix according to a predicate.  It
// will print a '1' if the predicate function is true, otherwise '0'. 
void PrintMatrix(std::predicate<int, int, int> auto f, int size)
{
  for(int y = 0; y < size; y++)
  {
    for(int x = 0; x < size; x++)
    {
      std::cout << " " << f(x, y, size);
    }
    std::cout << "\n";
  }
  std::cout << "\n";
}

int main()
{
  // a lambda to create diagonals
  auto diagonals = [](int x, int y, int size)
  {
    return x == y || ((size - x - 1) == y);
  };
  
  PrintMatrix(diagonals, 8);
  PrintMatrix(diagonals, 9);
}

</lang>
{{out}}
<pre> 1 0 0 0 0 0 0 1
 0 1 0 0 0 0 1 0
 0 0 1 0 0 1 0 0
 0 0 0 1 1 0 0 0
 0 0 0 1 1 0 0 0
 0 0 1 0 0 1 0 0
 0 1 0 0 0 0 1 0
 1 0 0 0 0 0 0 1

 1 0 0 0 0 0 0 0 1
 0 1 0 0 0 0 0 1 0
 0 0 1 0 0 0 1 0 0
 0 0 0 1 0 1 0 0 0
 0 0 0 0 1 0 0 0 0
 0 0 0 1 0 1 0 0 0
 0 0 1 0 0 0 1 0 0
 0 1 0 0 0 0 0 1 0
 1 0 0 0 0 0 0 0 1
</pre>

=={{header|CLU}}==
<lang clu>matrix = array[array[int]]

diagonals = proc (size: int) returns (matrix)
    mat: matrix := matrix$new()
    for y: int in int$from_to(1, size) do
        line: array[int] := array[int]$new()
        for x: int in int$from_to(1, size) do
            n: int
            if x=y cor size-x=y-1 
                then n := 1
                else n := 0
            end
            array[int]$addh(line, n)
        end
        matrix$addh(mat, line)
    end
    return(mat)
end diagonals

print_matrix = proc (s: stream, mat: matrix)
    for line: array[int] in matrix$elements(mat) do
        for elem: int in array[int]$elements(line) do   
            stream$puts(s, " " || int$unparse(elem))
        end
        stream$putl(s, "")
    end
end print_matrix

start_up = proc ()
    po: stream := stream$primary_output()
    print_matrix(po, diagonals(9))
    stream$putl(po, "")
    print_matrix(po, diagonals(10))
end start_up</lang>
{{out}}
<pre> 1 0 0 0 0 0 0 0 1
 0 1 0 0 0 0 0 1 0
 0 0 1 0 0 0 1 0 0
 0 0 0 1 0 1 0 0 0
 0 0 0 0 1 0 0 0 0
 0 0 0 1 0 1 0 0 0
 0 0 1 0 0 0 1 0 0
 0 1 0 0 0 0 0 1 0
 1 0 0 0 0 0 0 0 1

 1 0 0 0 0 0 0 0 0 1
 0 1 0 0 0 0 0 0 1 0
 0 0 1 0 0 0 0 1 0 0
 0 0 0 1 0 0 1 0 0 0
 0 0 0 0 1 1 0 0 0 0
 0 0 0 0 1 1 0 0 0 0
 0 0 0 1 0 0 1 0 0 0
 0 0 1 0 0 0 0 1 0 0
 0 1 0 0 0 0 0 0 1 0
 1 0 0 0 0 0 0 0 0 1</pre>

=={{header|Draco}}==
<lang draco>proc setDiagonals([*,*] byte matrix) void:
    word x, y, width, height;
    width := dim(matrix, 1);
    height := dim(matrix, 2);
    for x from 0 upto width-1 do
        for y from 0 upto height-1 do
            matrix[x,y] :=
                if x = y or width - x - 1 = y
                    then 1
                    else 0
                fi
        od
    od
corp

proc printMatrix([*,*] byte matrix) void:
    word x, y, width, height;
    width := dim(matrix, 1);
    height := dim(matrix, 2);
    for y from 0 upto height-1 do
        for x from 0 upto width-1 do
            write(' ', matrix[x,y]:1)
        od;
        writeln()
    od
corp

proc main() void:
    [9,9] byte m_odd;
    [10,10] byte m_even;
    
    setDiagonals(m_odd);
    printMatrix(m_odd);
    writeln();
    
    setDiagonals(m_even);
    printMatrix(m_even)
corp</lang>
{{out}}
<pre> 1 0 0 0 0 0 0 0 1
 0 1 0 0 0 0 0 1 0
 0 0 1 0 0 0 1 0 0
 0 0 0 1 0 1 0 0 0
 0 0 0 0 1 0 0 0 0
 0 0 0 1 0 1 0 0 0
 0 0 1 0 0 0 1 0 0
 0 1 0 0 0 0 0 1 0
 1 0 0 0 0 0 0 0 1

 1 0 0 0 0 0 0 0 0 1
 0 1 0 0 0 0 0 0 1 0
 0 0 1 0 0 0 0 1 0 0
 0 0 0 1 0 0 1 0 0 0
 0 0 0 0 1 1 0 0 0 0
 0 0 0 0 1 1 0 0 0 0
 0 0 0 1 0 0 1 0 0 0
 0 0 1 0 0 0 0 1 0 0
 0 1 0 0 0 0 0 0 1 0
 1 0 0 0 0 0 0 0 0 1</pre>

=={{header|Excel}}==
===LAMBDA===

Excel can lift functions over scalar values to functions over two-dimensional arrays.

Here we bind the name ''TwoDiagonalMatrix'' to a lambda expression in the Name Manager of the Excel WorkBook:

(See [https://www.microsoft.com/en-us/research/blog/lambda-the-ultimatae-excel-worksheet-function/ LAMBDA: The ultimate Excel worksheet function])

{{Works with|Office 365 betas 2021}}
<lang lisp>TwoDiagonalMatrix
=LAMBDA(n,
    LET(
        ixs, SEQUENCE(n, n, 0, 1),
        x, MOD(ixs, n),
        y, QUOTIENT(ixs, n),
        
        IF(x = y,
            1,
            IF(x = (n - y) - 1, 1, 0)
        )
    )
)</lang>
{{Out}}
The formulae in cells A2 and B2 populate the whole of each adjacent matrix.
{| class="wikitable" 
|-
|||style="text-align:right; font-family:serif; font-style:italic; font-size:120%;"|fx
! colspan="9" style="text-align:left; vertical-align: bottom; font-family:Arial, Helvetica, sans-serif !important;"|=TwoDiagonalMatrix(A2)
|- style="text-align:center; font-family:Arial, Helvetica, sans-serif !important; background-color:#000000; color:#ffffff;"
| 
| A
| B
| C
| D
| E
| F
| G
| H
| I
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| N
| Matrix
| 
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|-
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|-
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|-
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|}


Recent builds of Excel have also introduced a '''MAKEARRAY''' function, which takes a lambda expression as an argument.

Binding the name ''bothDiagonalMatrix'' in the Excel Name Manager:
<lang lisp>bothDiagonalMatrix
=LAMBDA(n,
    MAKEARRAY(
        n, n, 
        LAMBDA(
            x, y, 
            INT(OR(
                x = y, 
                x = (1 + n - y)
            ))
        )
    )
)</lang>
{{Out}}
{| class="wikitable" 
|-
|||style="text-align:right; font-family:serif; font-style:italic; font-size:120%;"|fx
! colspan="9" style="text-align:left; vertical-align: bottom; font-family:Arial, Helvetica, sans-serif !important;"|=bothDiagonalMatrix(A2)
|- style="text-align:center; font-family:Arial, Helvetica, sans-serif !important; background-color:#000000; color:#ffffff;"
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| N
| Matrix
| 
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| 
| 
|-
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|-
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|}

=={{header|F_Sharp|F#}}==
<lang fsharp>
// Matrix with two diagonals. Nigel Galloway: February 17th., 2022
let m11 m=Array2D.init m m (fun n g->if n=g || n+g=m-1 then 1 else 0)
printfn "%A\n\n%A" (m11 5) (m11 6)
</lang>
{{out}}
<pre>
[[1; 0; 0; 0; 1]
 [0; 1; 0; 1; 0]
 [0; 0; 1; 0; 0]
 [0; 1; 0; 1; 0]
 [1; 0; 0; 0; 1]]

[[1; 0; 0; 0; 0; 1]
 [0; 1; 0; 0; 1; 0]
 [0; 0; 1; 1; 0; 0]
 [0; 0; 1; 1; 0; 0]
 [0; 1; 0; 0; 1; 0]
 [1; 0; 0; 0; 0; 1]]
</pre>

=={{header|Factor}}==
{{works with|Factor|0.99 2021-06-02}}
<lang factor>USING: io kernel math math.matrices prettyprint ;

: <x-matrix> ( n -- matrix )
    dup dup 1 - '[ 2dup = -rot + _ = or 1 0 ? ] <matrix-by-indices> ;

6 <x-matrix> simple-table. nl
7 <x-matrix> simple-table.</lang>
{{out}}
<pre>
1 0 0 0 0 1
0 1 0 0 1 0
0 0 1 1 0 0
0 0 1 1 0 0
0 1 0 0 1 0
1 0 0 0 0 1

1 0 0 0 0 0 1
0 1 0 0 0 1 0
0 0 1 0 1 0 0
0 0 0 1 0 0 0
0 0 1 0 1 0 0
0 1 0 0 0 1 0
1 0 0 0 0 0 1
</pre>


=={{header|FreeBASIC}}==
===Text based===
<lang freebasic>Sub twoDiagonalMatrix(n As Integer)
    For i As Integer = 1 To n
        For j As Integer = 1 To n
            Print Iif((i = j) Or (i + j = n + 1), "1 ", "0 ");
        Next j
        Print
    Next i
End Sub

twoDiagonalMatrix(6)
Print
twoDiagonalMatrix(7)
Sleep</lang>
{{out}}
<pre>1 0 0 0 0 1
0 1 0 0 1 0
0 0 1 1 0 0
0 0 1 1 0 0
0 1 0 0 1 0
1 0 0 0 0 1

1 0 0 0 0 0 1
0 1 0 0 0 1 0
0 0 1 0 1 0 0
0 0 0 1 0 0 0
0 0 1 0 1 0 0
0 1 0 0 0 1 0
1 0 0 0 0 0 1</pre>

===Graphical===
<lang freebasic>Dim As Integer n = 8, size = 60 * n + 70
Screenres size, size, 24
Cls
Windowtitle "Matrix with two diagonals"

Dim As Integer beige = Rgb(245, 245, 220), brown = Rgb(171, 82, 54)

For x As Integer = 0 To n
    For y As Integer = 0 To n
        Dim As Integer cx = x*60 + 10
        Dim As Integer cy = y*60 + 10
        'If (x + y) Mod 2 = 0 Then
        If (x = y) Or (x + y = n) Then
            Line (cx,cy) - (cx+50, cy+50), brown, BF
            Draw String (cx + 20, cy + 20), "1", beige
        Else
            Line (cx,cy) - (cx+50, cy+50), beige, BF
        End If
    Next y
Next x
Bsave "twoDiagonalMatrix.bmp",0
Sleep</lang>
{{out}}
https://www.dropbox.com/s/ph9r28gpkp8ao8n/twoDiagonalMatrix.bmp?dl=0


=={{header|Fortran}}==
===Free form===
{{works with|Fortran 95}}
Fortran stores data in columns. Therefore, it should be checked whether instead of filling the matrix row by row (as below) it would be better to do it column by column. The profit would be cache hit optimization, better communication between CPU and RAM. Fortran allows you to zero the entire array, such as the a array below, simply by substituting a = 0. Unfortunately, an array 100x100 (that is, the choosen maximum size) would be filled with zeros even if, as in the example, we would need a much smaller array. You can also eliminate the variables j1 and j2 by replacing them with i and n - i + 1 respectively, but the source code would be slightly less readable.
<lang Fortran>program prog

    dimension a(100, 100)

    n = 7
	
    j1 = 1
    j2 = n
    do i = 1, n
        do j = 1, n
            a(i, j) = 0.
        end do
        a(i, j1) = 1
        a(i, j2) = 1
        j1 = j1 + 1
        j2 = j2 - 1
    end do

    do i = 1, n
        print *, (a(i, j), j=1,n)
    end do

end
</lang>
{{Output}}
<pre>
   1.00000000       0.00000000E+00   0.00000000E+00   0.00000000E+00   0.00000000E+00   0.00000000E+00   1.00000000    
   0.00000000E+00   1.00000000       0.00000000E+00   0.00000000E+00   0.00000000E+00   1.00000000       0.00000000E+00
   0.00000000E+00   0.00000000E+00   1.00000000       0.00000000E+00   1.00000000       0.00000000E+00   0.00000000E+00
   0.00000000E+00   0.00000000E+00   0.00000000E+00   1.00000000       0.00000000E+00   0.00000000E+00   0.00000000E+00
   0.00000000E+00   0.00000000E+00   1.00000000       0.00000000E+00   1.00000000       0.00000000E+00   0.00000000E+00
   0.00000000E+00   1.00000000       0.00000000E+00   0.00000000E+00   0.00000000E+00   1.00000000       0.00000000E+00
   1.00000000       0.00000000E+00   0.00000000E+00   0.00000000E+00   0.00000000E+00   0.00000000E+00   1.00000000      
</pre>
===Fixed form===
{{Works with|Fortran 77}}
Fortran is the oldest high-level programming language. It is constantly evolving and unfortunately there are no longer (or at least I do not have) computers on which to test whether the program works in the old Fortran IV or an even older dialect. The example below should be in Fortran IV, but unfortunately it was tested with a modern Fortran 2018 compiler, so even in legacy mode it is not Fortran IV but Fortran 77. However, it seems that it should work on CDC6000 mainframe ... if someone obviously has CDC6000.
<lang fortran>C DIAGONAL-DIAGONAL MATRIX IN FORTRAN 77

       PROGRAM PROG
 
       DIMENSION A(100, 100)
 
       N = 7

       A = 0.
       DO 10 I = 1, N
       A(I, I) = 1.
  10   A(I, N - I + 1) = 1.
 
       DO 20 I = 1, N
  20   PRINT *, (A(I, J), J=1,N)
 
       END</lang>

=={{header|Go}}==
{{trans|Wren}}
<lang go>package main

import "fmt"

func specialMatrix(n uint) {
    for i := uint(0); i < n; i++ {
        for j := uint(0); j < n; j++ {
            if i == j || i+j == n-1 {
                fmt.Printf("%d ", 1)
            } else {
                fmt.Printf("%d ", 0)
            }
        }
        fmt.Println()
    }
}

func main() {
    specialMatrix(8) // even n
    fmt.Println()
    specialMatrix(9) // odd n
}</lang>

{{out}}
<pre>
1 0 0 0 0 0 0 1 
0 1 0 0 0 0 1 0 
0 0 1 0 0 1 0 0 
0 0 0 1 1 0 0 0 
0 0 0 1 1 0 0 0 
0 0 1 0 0 1 0 0 
0 1 0 0 0 0 1 0 
1 0 0 0 0 0 0 1 

1 0 0 0 0 0 0 0 1 
0 1 0 0 0 0 0 1 0 
0 0 1 0 0 0 1 0 0 
0 0 0 1 0 1 0 0 0 
0 0 0 0 1 0 0 0 0 
0 0 0 1 0 1 0 0 0 
0 0 1 0 0 0 1 0 0 
0 1 0 0 0 0 0 1 0 
1 0 0 0 0 0 0 0 1 
</pre>

=={{header|Haskell}}==
<lang haskell>---------------- MATRIX WITH TWO DIAGONALS ---------------

twoDiagonalMatrix :: Int -> [[Int]]
twoDiagonalMatrix n = flip (fmap . go) xs <$> xs
  where
    xs = [1 .. n]
    go x y
      | y == x = 1
      | y == succ (subtract x n) = 1
      | otherwise = 0

--------------------------- TEST -------------------------
main :: IO ()
main =
  mapM_ putStrLn $
    unlines . fmap (((' ' :) . show) =<<)
      . twoDiagonalMatrix
      <$> [7, 8]</lang>


Or, in the form of a list comprehension:
<lang haskell>-------------- MATRIX WITH TWO DIAGONALS ---------------

twoDiagonalMatrix :: Int -> [[Int]]
twoDiagonalMatrix n =
  let xs = [1 .. n]
   in [ [ fromEnum $ x `elem` [y, succ (n - y)]
          | x <- xs
        ]
        | y <- xs
      ]

--------------------------- TEST -------------------------
main :: IO ()
main =
  mapM_ putStrLn $
    unlines . fmap (((' ' :) . show) =<<)
      . twoDiagonalMatrix
      <$> [7, 8]</lang>
{{Out}}
<pre> 1 0 0 0 0 0 1
 0 1 0 0 0 1 0
 0 0 1 0 1 0 0
 0 0 0 1 0 0 0
 0 0 1 0 1 0 0
 0 1 0 0 0 1 0
 1 0 0 0 0 0 1

 1 0 0 0 0 0 0 1
 0 1 0 0 0 0 1 0
 0 0 1 0 0 1 0 0
 0 0 0 1 1 0 0 0
 0 0 0 1 1 0 0 0
 0 0 1 0 0 1 0 0
 0 1 0 0 0 0 1 0
 1 0 0 0 0 0 0 1</pre>


and in terms of the Data.Matrix library:
<lang haskell>import Data.Matrix

twoDiagonals :: Int -> Matrix Int
twoDiagonals n =
  matrix
    n
    n
    (\(a, b) -> fromEnum $ a `elem` [b, succ (n - b)])

main :: IO ()
main =
  mapM_ print $ twoDiagonals <$> [7, 8]</lang>
{{Out}}
<pre>┌               ┐
│ 1 0 0 0 0 0 1 │
│ 0 1 0 0 0 1 0 │
│ 0 0 1 0 1 0 0 │
│ 0 0 0 1 0 0 0 │
│ 0 0 1 0 1 0 0 │
│ 0 1 0 0 0 1 0 │
│ 1 0 0 0 0 0 1 │
└               ┘
┌                 ┐
│ 1 0 0 0 0 0 0 1 │
│ 0 1 0 0 0 0 1 0 │
│ 0 0 1 0 0 1 0 0 │
│ 0 0 0 1 1 0 0 0 │
│ 0 0 0 1 1 0 0 0 │
│ 0 0 1 0 0 1 0 0 │
│ 0 1 0 0 0 0 1 0 │
│ 1 0 0 0 0 0 0 1 │
└                 ┘</pre>

=={{header|J}}==

Implementation:

<lang J>task=: {{(+.|.)=i.y}}</lang>

In other words, generate an order n identity matrix, flip it and (treating it as a bit matrix) OR the two matrices.

Some examples:

<lang J>   task 2
1 1
1 1
   task 3
1 0 1
0 1 0
1 0 1
   task 4
1 0 0 1
0 1 1 0
0 1 1 0
1 0 0 1
   task 5
1 0 0 0 1
0 1 0 1 0
0 0 1 0 0
0 1 0 1 0
1 0 0 0 1
   task 6
1 0 0 0 0 1
0 1 0 0 1 0
0 0 1 1 0 0
0 0 1 1 0 0
0 1 0 0 1 0
1 0 0 0 0 1</lang>

=={{header|Java}}==
The "Java philosophy" is the object-oriented paradigm. The example solution given below is therefore somewhat incomplete. We should first declare the matrix as an interface (or abstract class), then create a whole hierarchy of subclasses where DiagonalDiagonalMatrix would be a subclass of SquareMatrix or something like that. Of course, it's a gigantic job, but as a result we would have a library competing with Matlab / Octave etc., compliant with SOLID principles.
<lang java>package example.diagdiag;

public class Program {

    public static void main(String[] args) {
        DiagonalDiagonalMatrix A = new DiagonalDiagonalMatrix(7);
        System.out.println(A);
    }

}

class DiagonalDiagonalMatrix {

    final int n;
    private double[][] a = null;

    public Matrix(int n) {
        this.n = n;
    }

    public double get(int i, int j) {
        if (a == null) {
            return (i == j || i == n - j + 1) ? 1.0 : 0.0;
        } else {
            return a[i - 1][j - 1];
        }
    }

// Not necessary for the task: a lazy creation of the dense matrix.
//
//    public void put(int i, int j, double value) {
//        if (a == null) {
//            a = new double[n][n];
//            for (int p = 1; p <= n; i++) {
//                for (int q = 1; q <= n; j++) {
//                    a[p - 1][q - 1] = get(p, q);
//                }
//            }
//        }
//        a[i - 1][j - 1] = value;
//    }

    @Override
    public String toString() {
        StringBuilder sb = new StringBuilder();
        for (int i = 1; i <= n; i++) {
            for (int j = 1; j <= n; j++) {
                sb.append('\t');
                sb.append(get(i, j));
            }
            sb.append('\n');
        }
        return sb.toString();
    }

}</lang>
{{Output}}
<pre>	1.0	0.0	0.0	0.0	0.0	0.0	1.0
	0.0	1.0	0.0	0.0	0.0	1.0	0.0
	0.0	0.0	1.0	0.0	1.0	0.0	0.0
	0.0	0.0	0.0	1.0	0.0	0.0	0.0
	0.0	0.0	1.0	0.0	1.0	0.0	0.0
	0.0	1.0	0.0	0.0	0.0	1.0	0.0
	1.0	0.0	0.0	0.0	0.0	0.0	1.0</pre>

=={{header|JavaScript}}==
<lang javascript>(() => {
    "use strict";

    // ------------ MATRIX WITH TWO DIAGONALS ------------

    // doubleDiagonal :: Int -> [[Int]]
    const doubleDiagonal = n => {
        // A square matrix of dimension n with ones
        // along both diagonals, and zeros elsewhere.
        const xs = enumFromTo(1)(n);

        return xs.map(
            y => xs.map(
                x => Number(
                    [y, 1 + n - y].includes(x)
                )
            )
        );
    };


    // ---------------------- TEST -----------------------
    const main = () => [7, 8].map(
        n => showMatrix(
            doubleDiagonal(n)
        )
    ).join("\n\n");


    // --------------------- GENERIC ---------------------

    // enumFromTo :: Int -> Int -> [Int]
    const enumFromTo = m =>
        n => Array.from({
            length: 1 + n - m
        }, (_, i) => m + i);


    // showMatrix :: [[a]] -> String
    const showMatrix = rows =>
        // String representation of a matrix.
        rows.map(
            row => row.map(String).join(" ")
        ).join("\n");


    // MAIN --
    return main();
})();</lang>


Or, in terms of a more general matrix function:
<lang javascript>(() => {
    "use strict";

    // ------------ MATRIX WITH TWO DIAGONALS ------------

    // bothDiagonals :: Int -> [[Int]]
    const bothDiagonals = n =>
        matrix(n)(n)(
            y => x => Number(
                [y, (n - y) - 1].includes(x)
            )
        );


    // ---------------------- TEST -----------------------
    const main = () => [7, 8].map(
        compose(
            showMatrix,
            bothDiagonals
        )
    ).join("\n\n");


    // --------------------- GENERIC ---------------------

    // compose (<<<) :: (b -> c) -> (a -> b) -> a -> c
    const compose = (...fs) =>
        // A function defined by the right-to-left
        // composition of all the functions in fs.
        fs.reduce(
            (f, g) => x => f(g(x)),
            x => x
        );


    // matrix Int -> Int -> (Int -> Int -> a) -> [[a]]
    const matrix = nRows => nCols =>
        // A matrix of a given number of columns and rows,
        // in which each value is a given function of its
        // (zero-based) column and row indices.
        f => Array.from({
            length: nRows
        }, (_, iRow) => Array.from({
            length: nCols
        }, (__, iCol) => f(iRow)(iCol)));


    // showMatrix :: [[a]] -> String
    const showMatrix = rows =>
        // String representation of a matrix.
        rows.map(
            row => row.map(String).join(" ")
        ).join("\n");

    // MAIN ---
    return main();
})();</lang>
{{Out}}
<pre>1 0 0 0 0 0 1
0 1 0 0 0 1 0
0 0 1 0 1 0 0
0 0 0 1 0 0 0
0 0 1 0 1 0 0
0 1 0 0 0 1 0
1 0 0 0 0 0 1

1 0 0 0 0 0 0 1
0 1 0 0 0 0 1 0
0 0 1 0 0 1 0 0
0 0 0 1 1 0 0 0
0 0 0 1 1 0 0 0
0 0 1 0 0 1 0 0
0 1 0 0 0 0 1 0
1 0 0 0 0 0 0 1</pre>

=={{header|jq}}==
{{works with|jq}}
'''Works with gojq, the Go implementation of jq'''
<lang jq>def bidiagonal_matrix:
  . as $n
  | [range(0; $n) | 0] as $z
  | reduce range(0; $n) as $i ([];
      . + [$z | .[$i] = 1 | .[$n-$i-1] = 1] );

def display:
  map(join(" ")) | join("\n");</lang>
'''Example'''
<lang jq>9|bidiagonal_matrix|display</lang>
{{out}}
<pre>
1 0 0 0 0 0 0 0 1
0 1 0 0 0 0 0 1 0
0 0 1 0 0 0 1 0 0
0 0 0 1 0 1 0 0 0
0 0 0 0 1 0 0 0 0
0 0 0 1 0 1 0 0 0
0 0 1 0 0 0 1 0 0
0 1 0 0 0 0 0 1 0
1 0 0 0 0 0 0 0 1
</pre>

=={{header|Julia}}==
<lang julia>
julia> twodiagonalmat(n) = [Int(i == j || i == n - j + 1) for j in 1:n, i in 1:n]
twodiagonalmat (generic function with 1 method)

julia> twodiagonalmat(1)
1×1 Matrix{Int64}:
 1

julia> twodiagonalmat(2)
2×2 Matrix{Int64}:
 1  1
 1  1

julia> twodiagonalmat(3)
3×3 Matrix{Int64}:
 1  0  1
 0  1  0
 1  0  1

julia> twodiagonalmat(4)
4×4 Matrix{Int64}:
 1  0  0  1
 0  1  1  0
 0  1  1  0
 1  0  0  1

julia> twodiagonalmat(5)
5×5 Matrix{Int64}:
 1  0  0  0  1
 0  1  0  1  0
 0  0  1  0  0
 0  1  0  1  0
 1  0  0  0  1
</lang>
=== Sparse matrix version ===
<lang julia>julia> using LinearAlgebra

julia> twodiagonalsparse(n) = I(n) .| rotl90(I(n))
twodiagonalsparse (generic function with 1 method)

julia> twodiagonalsparse(7)
7×7 SparseArrays.SparseMatrixCSC{Bool, Int64} with 13 stored entries:
 1  ⋅  ⋅  ⋅  ⋅  ⋅  1
 ⋅  1  ⋅  ⋅  ⋅  1  ⋅
 ⋅  ⋅  1  ⋅  1  ⋅  ⋅
 ⋅  ⋅  ⋅  1  ⋅  ⋅  ⋅
 ⋅  ⋅  1  ⋅  1  ⋅  ⋅
 ⋅  1  ⋅  ⋅  ⋅  1  ⋅
 1  ⋅  ⋅  ⋅  ⋅  ⋅  1

julia> twodiagonalsparse(8)
8×8 SparseArrays.SparseMatrixCSC{Bool, Int64} with 16 stored entries:
 1  ⋅  ⋅  ⋅  ⋅  ⋅  ⋅  1
 ⋅  1  ⋅  ⋅  ⋅  ⋅  1  ⋅
 ⋅  ⋅  1  ⋅  ⋅  1  ⋅  ⋅
 ⋅  ⋅  ⋅  1  1  ⋅  ⋅  ⋅
 ⋅  ⋅  ⋅  1  1  ⋅  ⋅  ⋅
 ⋅  ⋅  1  ⋅  ⋅  1  ⋅  ⋅
 ⋅  1  ⋅  ⋅  ⋅  ⋅  1  ⋅
 1  ⋅  ⋅  ⋅  ⋅  ⋅  ⋅  1
</lang>

=={{header|Matlab}}==
<lang Matlab>function A = diagdiag(N, sparse)
% Create an diagonal-diagonal square matrix.
%
% Parameters:
% 
%   N      -- number of rows (columns);
%   sparse -- should be true to create a sparse matrix,
%             default false (dense matrix).
%
% Return:
%
%   A matrix where all elements A(i, j) are zero except
%   elements on the diagonal or on the back-diagonal.
%   The diagonal (and back-diagonal) elements are equal 1.
    
    if nargin < 2
        sparse = false;
    end        
    
    if sparse
        A = speye(N);
    else
        A = eye(N);
    end
    
    A = fliplr(A);
    A(1:N+1:end) = 1;
end</lang>
{{Output}}
<pre>
>> diagdiag(7)

ans =

  Columns 1 through 7

     1     0     0     0     0     0     1
     0     1     0     0     0     1     0
     0     0     1     0     1     0     0
     0     0     0     1     0     0     0
     0     0     1     0     1     0     0
     0     1     0     0     0     1     0
     1     0     0     0     0     0     1

>> diagdiag(7, true)

ans =

   (1,1)        1
   (7,1)        1
   (2,2)        1
   (6,2)        1
   (3,3)        1
   (5,3)        1
   (4,4)        1
   (3,5)        1
   (5,5)        1
   (2,6)        1
   (6,6)        1
   (1,7)        1
   (7,7)        1
</pre>

=={{header|Pascal}}==
<lang pascal>program diagonaldiagonal;
const N = 7;
type
    index = 1..N;
var 
    a : array[index, index] of real;
    i, j, j1, j2 : index;
begin
    for i := 1 to N do
    begin
        for j := 1 to N do
            a[i, j] := 0.0;
        j1 := i;
        j2 := N - i + 1;
        a[i, j1] := 1.0;
        a[i, j2] := 1.0;
    end;
    
    for i := 1 to N do
    begin
        for j := 1 to N do
            write(a[i, j]:2:0);
        writeln();
    end
end.
</lang>
{{Output}}
<pre> 1 0 0 0 0 0 1
 0 1 0 0 0 1 0
 0 0 1 0 1 0 0
 0 0 0 1 0 0 0
 0 0 1 0 1 0 0
 0 1 0 0 0 1 0
 1 0 0 0 0 0 1
</pre>

=={{header|Perl}}==
===Strings===
<lang perl>#!/usr/bin/perl

use strict; #https://rosettacode.org/wiki/Matrix_with_two_diagonals
use warnings;

print diagonal($_), "\n" for 10, 11;

sub diagonal
  {
  my $n =  shift() - 1;
  local $_ = 1 . 0 x ($n - 1) . 2 . "\n" . (0 . 0 x $n . "\n") x $n;
  1 while s/(?<=1...{$n})0/1/s or s/(?<=2.{$n})[01]/2/s;
  return tr/2/1/r =~ s/\B/ /gr;
  }</lang>
{{out}}
<pre>1 0 0 0 0 0 0 0 0 1
0 1 0 0 0 0 0 0 1 0
0 0 1 0 0 0 0 1 0 0
0 0 0 1 0 0 1 0 0 0
0 0 0 0 1 1 0 0 0 0
0 0 0 0 1 1 0 0 0 0
0 0 0 1 0 0 1 0 0 0
0 0 1 0 0 0 0 1 0 0
0 1 0 0 0 0 0 0 1 0
1 0 0 0 0 0 0 0 0 1
 
1 0 0 0 0 0 0 0 0 0 1
0 1 0 0 0 0 0 0 0 1 0
0 0 1 0 0 0 0 0 1 0 0
0 0 0 1 0 0 0 1 0 0 0
0 0 0 0 1 0 1 0 0 0 0
0 0 0 0 0 1 0 0 0 0 0
0 0 0 0 1 0 1 0 0 0 0
0 0 0 1 0 0 0 1 0 0 0
0 0 1 0 0 0 0 0 1 0 0
0 1 0 0 0 0 0 0 0 1 0
1 0 0 0 0 0 0 0 0 0 1</pre>

===Numbers===
<lang perl>use strict;
use warnings;
use feature 'say';

sub dual_diagonal {
    my($n) = shift() - 1;
    my @m;
    for (0..$n) {
        my @rr = reverse my @r = ( (0) x $_, 1, (0) x ($n-$_) );
        push @m, [ map { $r[$_] or $rr[$_] } 0..$n ]
    }
    @m
}

say join ' ', @$_ for dual_diagonal(4); say '';
say join ' ', @$_ for dual_diagonal(5);
</lang>
{{out}}
<pre>1 0 0 1
0 1 1 0
0 1 1 0
1 0 0 1

1 0 0 0 1
0 1 0 1 0
0 0 1 0 0
0 1 0 1 0
1 0 0 0 1</pre>

=={{header|Phix}}==
===numbers===
Tee hee, pick the bones out of this one. ''Lovely.''
<!--<lang Phix>(phixonline)-->
 <span style="color: #008080;">with</span> <span style="color: #008080;">javascript_semantics</span>
 <span style="color: #008080;">for</span> <span style="color: #000000;">n</span><span style="color: #0000FF;">=</span><span style="color: #000000;">6</span> <span style="color: #008080;">to</span> <span style="color: #000000;">7</span> <span style="color: #008080;">do</span>
     <span style="color: #7060A8;">pp</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">apply</span><span style="color: #0000FF;">(</span><span style="color: #004600;">true</span><span style="color: #0000FF;">,</span><span style="color: #7060A8;">reinstate</span><span style="color: #0000FF;">,{</span><span style="color: #7060A8;">repeat</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">repeat</span><span style="color: #0000FF;">(</span><span style="color: #000000;">0</span><span style="color: #0000FF;">,</span><span style="color: #000000;">n</span><span style="color: #0000FF;">),</span><span style="color: #000000;">n</span><span style="color: #0000FF;">),</span><span style="color: #7060A8;">apply</span><span style="color: #0000FF;">(</span><span style="color: #004600;">true</span><span style="color: #0000FF;">,</span><span style="color: #7060A8;">sq_mul</span><span style="color: #0000FF;">,{</span><span style="color: #7060A8;">tagset</span><span style="color: #0000FF;">(</span><span style="color: #000000;">n</span><span style="color: #0000FF;">),{{</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">}}}),{{</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">1</span><span style="color: #0000FF;">}}}),{</span><span style="color: #004600;">pp_Nest</span><span style="color: #0000FF;">,</span><span style="color: #000000;">1</span><span style="color: #0000FF;">})</span>
 <span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
<!--</lang>-->
{{out}}
<pre>
{{1,0,0,0,0,1},
 {0,1,0,0,1,0},
 {0,0,1,1,0,0},
 {0,0,1,1,0,0},
 {0,1,0,0,1,0},
 {1,0,0,0,0,1}}
{{1,0,0,0,0,0,1},
 {0,1,0,0,0,1,0},
 {0,0,1,0,1,0,0},
 {0,0,0,1,0,0,0},
 {0,0,1,0,1,0,0},
 {0,1,0,0,0,1,0},
 {1,0,0,0,0,0,1}}
</pre>
Slightly saner, shows sackly same stuff:
<!--<lang Phix>(phixonline)-->
 <span style="color: #008080;">with</span> <span style="color: #008080;">javascript_semantics</span>
 <span style="color: #008080;">for</span> <span style="color: #000000;">n</span><span style="color: #0000FF;">=</span><span style="color: #000000;">6</span> <span style="color: #008080;">to</span> <span style="color: #000000;">7</span> <span style="color: #008080;">do</span>
     <span style="color: #004080;">sequence</span> <span style="color: #000000;">s</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">repeat</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">repeat</span><span style="color: #0000FF;">(</span><span style="color: #000000;">0</span><span style="color: #0000FF;">,</span><span style="color: #000000;">n</span><span style="color: #0000FF;">),</span><span style="color: #000000;">n</span><span style="color: #0000FF;">)</span>
     <span style="color: #008080;">for</span> <span style="color: #000000;">i</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #000000;">n</span> <span style="color: #008080;">do</span>
         <span style="color: #000000;">s</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">][</span><span style="color: #000000;">i</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">1</span>
         <span style="color: #000000;">s</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">][-</span><span style="color: #000000;">i</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">1</span>
     <span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
     <span style="color: #7060A8;">pp</span><span style="color: #0000FF;">(</span><span style="color: #000000;">s</span><span style="color: #0000FF;">,{</span><span style="color: #004600;">pp_Nest</span><span style="color: #0000FF;">,</span><span style="color: #000000;">1</span><span style="color: #0000FF;">})</span>
 <span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
<!--</lang>-->
===strings===
<!--<lang Phix>(phixonline)-->
 <span style="color: #008080;">with</span> <span style="color: #008080;">javascript_semantics</span>
 <span style="color: #008080;">for</span> <span style="color: #000000;">n</span><span style="color: #0000FF;">=</span><span style="color: #000000;">6</span> <span style="color: #008080;">to</span> <span style="color: #000000;">7</span> <span style="color: #008080;">do</span>
     <span style="color: #004080;">sequence</span> <span style="color: #000000;">s</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">repeat</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">join</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">repeat</span><span style="color: #0000FF;">(</span><span style="color: #008000;">'0'</span><span style="color: #0000FF;">,</span><span style="color: #000000;">n</span><span style="color: #0000FF;">),</span><span style="color: #008000;">' '</span><span style="color: #0000FF;">),</span><span style="color: #000000;">n</span><span style="color: #0000FF;">)</span>
     <span style="color: #008080;">for</span> <span style="color: #000000;">i</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #000000;">n</span> <span style="color: #008080;">do</span>
         <span style="color: #004080;">integer</span> <span style="color: #000000;">j</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">2</span><span style="color: #0000FF;">*</span><span style="color: #000000;">i</span><span style="color: #0000FF;">-</span><span style="color: #000000;">1</span>
         <span style="color: #000000;">s</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">][</span><span style="color: #000000;">j</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #008000;">'1'</span>
         <span style="color: #000000;">s</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">][-</span><span style="color: #000000;">j</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #008000;">'1'</span>
     <span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
     <span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"%s\n\n"</span><span style="color: #0000FF;">,{</span><span style="color: #7060A8;">join</span><span style="color: #0000FF;">(</span><span style="color: #000000;">s</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"\n"</span><span style="color: #0000FF;">)})</span>
 <span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
<!--</lang>-->
{{out}}
<pre>
1 0 0 0 0 1
0 1 0 0 1 0
0 0 1 1 0 0
0 0 1 1 0 0
0 1 0 0 1 0
1 0 0 0 0 1

1 0 0 0 0 0 1
0 1 0 0 0 1 0
0 0 1 0 1 0 0
0 0 0 1 0 0 0
0 0 1 0 1 0 0
0 1 0 0 0 1 0
1 0 0 0 0 0 1
</pre>
===GUI/online===
{{libheader|Phix/pGUI}}
{{libheader|Phix/online}}
Based on [[2048#Phix]], and uses the same colour and font choices.
You can run this online [http://phix.x10.mx/p2js/strange_identity_matrices.htm here].
<!--<lang Phix>(phixonline)-->
 <span style="color: #008080;">with</span> <span style="color: #008080;">javascript_semantics</span>
 <span style="color: #008080;">include</span> <span style="color: #000000;">pGUI</span><span style="color: #0000FF;">.</span><span style="color: #000000;">e</span>
 
 <span style="color: #008080;">constant</span> <span style="color: #000000;">TITLE</span> <span style="color: #0000FF;">=</span> <span style="color: #008000;">"Strange Identity Matrices"</span><span style="color: #0000FF;">,</span>
          <span style="color: #000000;">HELPTXT</span> <span style="color: #0000FF;">=</span> <span style="color: #008000;">"""
 Press F1 to see this help text.
 Press +/- to increase or decrease the matrix size
 Press 'M' for a mosaic pattern
 Press 'O' for outer or four sides of a square
 Press 'X' for two diagonals
 The window can be fully resized
 (MINSIZE does not yet work in a browser)
 """</span>
 
 <span style="color: #008080;">function</span> <span style="color: #000000;">help</span><span style="color: #0000FF;">()</span>
     <span style="color: #7060A8;">IupMessage</span><span style="color: #0000FF;">(</span><span style="color: #000000;">TITLE</span><span style="color: #0000FF;">,</span><span style="color: #000000;">HELPTXT</span><span style="color: #0000FF;">,</span><span style="color: #000000;">bWrap</span><span style="color: #0000FF;">:=</span><span style="color: #004600;">false</span><span style="color: #0000FF;">)</span>
     <span style="color: #008080;">return</span> <span style="color: #004600;">IUP_DEFAULT</span>
 <span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
 
 <span style="color: #004080;">Ihandle</span> <span style="color: #000000;">canvas</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">dlg</span>
 <span style="color: #004080;">cdCanvas</span> <span style="color: #000000;">cddbuffer</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">cdcanvas</span>
 
 <span style="color: #004080;">sequence</span> <span style="color: #000000;">board</span>
 <span style="color: #004080;">integer</span> <span style="color: #000000;">n</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">5</span><span style="color: #0000FF;">,</span>
         <span style="color: #000000;">mtype</span> <span style="color: #0000FF;">=</span> <span style="color: #008000;">'X'</span> <span style="color: #000080;font-style:italic;">-- (two diags) or 'O'uter or 'M'osaic</span>
 
 <span style="color: #008080;">function</span> <span style="color: #000000;">mosaic</span><span style="color: #0000FF;">()</span>
     <span style="color: #008080;">for</span> <span style="color: #000000;">y</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #000000;">n</span> <span style="color: #008080;">do</span>
         <span style="color: #008080;">for</span> <span style="color: #000000;">x</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span><span style="color: #0000FF;">+</span><span style="color: #7060A8;">odd</span><span style="color: #0000FF;">(</span><span style="color: #000000;">n</span><span style="color: #0000FF;">+</span><span style="color: #000000;">y</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">to</span> <span style="color: #000000;">n</span> <span style="color: #008080;">by</span> <span style="color: #000000;">2</span> <span style="color: #008080;">do</span>
             <span style="color: #000000;">board</span><span style="color: #0000FF;">[</span><span style="color: #000000;">y</span><span style="color: #0000FF;">][</span><span style="color: #000000;">x</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #008000;">"1"</span>
         <span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
     <span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
     <span style="color: #008080;">return</span> <span style="color: #008000;">"mosaic"</span>
 <span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
 
 <span style="color: #008080;">function</span> <span style="color: #000000;">outer</span><span style="color: #0000FF;">()</span>
     <span style="color: #008080;">for</span> <span style="color: #000000;">y</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #000000;">n</span> <span style="color: #008080;">do</span>
         <span style="color: #004080;">integer</span> <span style="color: #000000;">step</span> <span style="color: #0000FF;">=</span> <span style="color: #008080;">iff</span><span style="color: #0000FF;">(</span><span style="color: #000000;">y</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">or</span> <span style="color: #000000;">y</span><span style="color: #0000FF;">=</span><span style="color: #000000;">n</span><span style="color: #0000FF;">?</span><span style="color: #000000;">1</span><span style="color: #0000FF;">:</span><span style="color: #000000;">n</span><span style="color: #0000FF;">-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">)</span>
         <span style="color: #008080;">for</span> <span style="color: #000000;">x</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #000000;">n</span> <span style="color: #008080;">by</span> <span style="color: #000000;">step</span> <span style="color: #008080;">do</span>
             <span style="color: #000000;">board</span><span style="color: #0000FF;">[</span><span style="color: #000000;">y</span><span style="color: #0000FF;">][</span><span style="color: #000000;">x</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #008000;">"1"</span>
         <span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
     <span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
     <span style="color: #008080;">return</span> <span style="color: #008000;">"four sides"</span>
 <span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
 
 <span style="color: #008080;">function</span> <span style="color: #000000;">diag</span><span style="color: #0000FF;">()</span>
     <span style="color: #008080;">for</span> <span style="color: #000000;">i</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #000000;">n</span> <span style="color: #008080;">do</span>
         <span style="color: #000000;">board</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">][</span><span style="color: #000000;">i</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #008000;">"1"</span>
         <span style="color: #000000;">board</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">][-</span><span style="color: #000000;">i</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #008000;">"1"</span>
     <span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
     <span style="color: #008080;">return</span> <span style="color: #008000;">"two diagonals"</span>
 <span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
 
 <span style="color: #008080;">function</span> <span style="color: #000000;">redraw_cb</span><span style="color: #0000FF;">(</span><span style="color: #004080;">Ihandle</span> <span style="color: #000080;font-style:italic;">/*ih*/</span><span style="color: #0000FF;">)</span>
     <span style="color: #004080;">integer</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">dw</span><span style="color: #0000FF;">,</span><span style="color: #000000;">dh</span><span style="color: #0000FF;">}</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">IupGetIntInt</span><span style="color: #0000FF;">(</span><span style="color: #000000;">canvas</span><span style="color: #0000FF;">,</span> <span style="color: #008000;">"DRAWSIZE"</span><span style="color: #0000FF;">),</span>
             <span style="color: #000000;">ms</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">n</span><span style="color: #0000FF;">*</span><span style="color: #000000;">5</span><span style="color: #0000FF;">+</span><span style="color: #000000;">5</span><span style="color: #0000FF;">,</span>                 <span style="color: #000080;font-style:italic;">-- margin space</span>
             <span style="color: #000000;">mx</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">min</span><span style="color: #0000FF;">(</span><span style="color: #000000;">dw</span><span style="color: #0000FF;">,</span><span style="color: #000000;">dh</span><span style="color: #0000FF;">)-</span><span style="color: #000000;">ms</span><span style="color: #0000FF;">,</span>         <span style="color: #000080;font-style:italic;">-- max size</span>
             <span style="color: #000000;">ts</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">floor</span><span style="color: #0000FF;">(</span><span style="color: #000000;">mx</span><span style="color: #0000FF;">/</span><span style="color: #000000;">n</span><span style="color: #0000FF;">),</span>           <span style="color: #000080;font-style:italic;">-- max tile size</span>
             <span style="color: #000000;">th</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">floor</span><span style="color: #0000FF;">(</span><span style="color: #000000;">ts</span><span style="color: #0000FF;">/</span><span style="color: #000000;">2</span><span style="color: #0000FF;">),</span>           <span style="color: #000080;font-style:italic;">-- for text posn</span>
             <span style="color: #000000;">os</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">ts</span><span style="color: #0000FF;">*</span><span style="color: #000000;">n</span><span style="color: #0000FF;">+</span><span style="color: #000000;">ms</span><span style="color: #0000FF;">,</span>               <span style="color: #000080;font-style:italic;">-- overall size</span>
             <span style="color: #000000;">ox</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">floor</span><span style="color: #0000FF;">((</span><span style="color: #000000;">dw</span><span style="color: #0000FF;">-</span><span style="color: #000000;">os</span><span style="color: #0000FF;">)/</span><span style="color: #000000;">2</span><span style="color: #0000FF;">),</span>      <span style="color: #000080;font-style:italic;">-- top right x</span>
             <span style="color: #000000;">oy</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">floor</span><span style="color: #0000FF;">((</span><span style="color: #000000;">dh</span><span style="color: #0000FF;">-</span><span style="color: #000000;">os</span><span style="color: #0000FF;">)/</span><span style="color: #000000;">2</span><span style="color: #0000FF;">),</span>      <span style="color: #000080;font-style:italic;">-- top right y</span>
             <span style="color: #000000;">font_size</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">floor</span><span style="color: #0000FF;">((</span><span style="color: #000000;">ts</span><span style="color: #0000FF;">+</span><span style="color: #000000;">10</span><span style="color: #0000FF;">)/</span><span style="color: #000000;">2</span><span style="color: #0000FF;">)</span>
 
     <span style="color: #000000;">board</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">repeat</span><span style="color: #0000FF;">(</span><span style="color: #7060A8;">repeat</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"0"</span><span style="color: #0000FF;">,</span><span style="color: #000000;">n</span><span style="color: #0000FF;">),</span><span style="color: #000000;">n</span><span style="color: #0000FF;">)</span>
     <span style="color: #004080;">string</span> <span style="color: #000000;">title</span>
     <span style="color: #008080;">switch</span> <span style="color: #000000;">mtype</span> <span style="color: #008080;">do</span>
         <span style="color: #008080;">case</span> <span style="color: #008000;">'M'</span><span style="color: #0000FF;">:</span> <span style="color: #000000;">title</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">mosaic</span><span style="color: #0000FF;">()</span>
         <span style="color: #008080;">case</span> <span style="color: #008000;">'O'</span><span style="color: #0000FF;">:</span> <span style="color: #000000;">title</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">outer</span><span style="color: #0000FF;">()</span>
         <span style="color: #008080;">case</span> <span style="color: #008000;">'X'</span><span style="color: #0000FF;">:</span> <span style="color: #000000;">title</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">diag</span><span style="color: #0000FF;">()</span>
     <span style="color: #008080;">end</span> <span style="color: #008080;">switch</span>
     <span style="color: #7060A8;">IupSetStrAttribute</span><span style="color: #0000FF;">(</span><span style="color: #000000;">dlg</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"TITLE"</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"%s (%dx%d, %s)"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">TITLE</span><span style="color: #0000FF;">,</span><span style="color: #000000;">n</span><span style="color: #0000FF;">,</span><span style="color: #000000;">n</span><span style="color: #0000FF;">,</span><span style="color: #000000;">title</span><span style="color: #0000FF;">})</span>
 
     <span style="color: #7060A8;">cdCanvasActivate</span><span style="color: #0000FF;">(</span><span style="color: #000000;">cddbuffer</span><span style="color: #0000FF;">)</span>
     <span style="color: #7060A8;">cdCanvasSetBackground</span><span style="color: #0000FF;">(</span><span style="color: #000000;">cddbuffer</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">#FAF8EF</span><span style="color: #0000FF;">)</span>
     <span style="color: #7060A8;">cdCanvasClear</span><span style="color: #0000FF;">(</span><span style="color: #000000;">cddbuffer</span><span style="color: #0000FF;">)</span>
     <span style="color: #7060A8;">cdCanvasSetForeground</span><span style="color: #0000FF;">(</span><span style="color: #000000;">cddbuffer</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">#BBADA0</span><span style="color: #0000FF;">)</span>
     <span style="color: #7060A8;">cdCanvasRoundedBox</span><span style="color: #0000FF;">(</span><span style="color: #000000;">cddbuffer</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">ox</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">ox</span><span style="color: #0000FF;">+</span><span style="color: #000000;">os</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">oy</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">oy</span><span style="color: #0000FF;">+</span><span style="color: #000000;">os</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">10</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">10</span><span style="color: #0000FF;">)</span>
     <span style="color: #7060A8;">cdCanvasFont</span><span style="color: #0000FF;">(</span><span style="color: #000000;">cddbuffer</span><span style="color: #0000FF;">,</span> <span style="color: #008000;">"Calibri"</span><span style="color: #0000FF;">,</span> <span style="color: #004600;">CD_BOLD</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">font_size</span><span style="color: #0000FF;">)</span>
 
     <span style="color: #004080;">integer</span> <span style="color: #000000;">tx</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">ox</span><span style="color: #0000FF;">+</span><span style="color: #000000;">5</span>
     <span style="color: #008080;">for</span> <span style="color: #000000;">y</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #000000;">n</span> <span style="color: #008080;">do</span>
         <span style="color: #004080;">integer</span> <span style="color: #000000;">ty</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">oy</span><span style="color: #0000FF;">+</span><span style="color: #000000;">5</span>
         <span style="color: #008080;">for</span> <span style="color: #000000;">x</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #000000;">n</span> <span style="color: #008080;">do</span>
             <span style="color: #004080;">string</span> <span style="color: #000000;">bxy</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">board</span><span style="color: #0000FF;">[</span><span style="color: #000000;">x</span><span style="color: #0000FF;">][</span><span style="color: #000000;">y</span><span style="color: #0000FF;">]</span>
             <span style="color: #7060A8;">cdCanvasSetForeground</span><span style="color: #0000FF;">(</span><span style="color: #000000;">cddbuffer</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">#EEE4DA</span><span style="color: #0000FF;">)</span>
             <span style="color: #7060A8;">cdCanvasRoundedBox</span><span style="color: #0000FF;">(</span><span style="color: #000000;">cddbuffer</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">tx</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">tx</span><span style="color: #0000FF;">+</span><span style="color: #000000;">ts</span><span style="color: #0000FF;">-</span><span style="color: #000000;">2</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">ty</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">ty</span><span style="color: #0000FF;">+</span><span style="color: #000000;">ts</span><span style="color: #0000FF;">-</span><span style="color: #000000;">2</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">5</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">5</span><span style="color: #0000FF;">)</span>
             <span style="color: #7060A8;">cdCanvasSetForeground</span><span style="color: #0000FF;">(</span><span style="color: #000000;">cddbuffer</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">#776E65</span><span style="color: #0000FF;">)</span>
             <span style="color: #7060A8;">cdCanvasText</span><span style="color: #0000FF;">(</span><span style="color: #000000;">cddbuffer</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">tx</span><span style="color: #0000FF;">+</span><span style="color: #000000;">th</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">ty</span><span style="color: #0000FF;">+</span><span style="color: #000000;">th</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">bxy</span><span style="color: #0000FF;">)</span> 
             <span style="color: #000000;">ty</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">ts</span><span style="color: #0000FF;">+</span><span style="color: #000000;">5</span>
         <span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
         <span style="color: #000000;">tx</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">ts</span><span style="color: #0000FF;">+</span><span style="color: #000000;">5</span>
     <span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
 
     <span style="color: #7060A8;">cdCanvasFlush</span><span style="color: #0000FF;">(</span><span style="color: #000000;">cddbuffer</span><span style="color: #0000FF;">)</span>
     <span style="color: #008080;">return</span> <span style="color: #004600;">IUP_DEFAULT</span>
 <span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
 
 <span style="color: #008080;">function</span> <span style="color: #000000;">map_cb</span><span style="color: #0000FF;">(</span><span style="color: #004080;">Ihandle</span> <span style="color: #000000;">ih</span><span style="color: #0000FF;">)</span>
     <span style="color: #000000;">cdcanvas</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">cdCreateCanvas</span><span style="color: #0000FF;">(</span><span style="color: #004600;">CD_IUP</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">ih</span><span style="color: #0000FF;">)</span>
     <span style="color: #000000;">cddbuffer</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">cdCreateCanvas</span><span style="color: #0000FF;">(</span><span style="color: #004600;">CD_DBUFFER</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">cdcanvas</span><span style="color: #0000FF;">)</span>
     <span style="color: #7060A8;">cdCanvasSetTextAlignment</span><span style="color: #0000FF;">(</span><span style="color: #000000;">cddbuffer</span><span style="color: #0000FF;">,</span> <span style="color: #004600;">CD_CENTER</span><span style="color: #0000FF;">)</span> 
     <span style="color: #008080;">return</span> <span style="color: #004600;">IUP_DEFAULT</span>
 <span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
 
 <span style="color: #008080;">function</span> <span style="color: #000000;">key_cb</span><span style="color: #0000FF;">(</span><span style="color: #004080;">Ihandle</span> <span style="color: #000080;font-style:italic;">/*ih*/</span><span style="color: #0000FF;">,</span> <span style="color: #004080;">atom</span> <span style="color: #000000;">c</span><span style="color: #0000FF;">)</span>
     <span style="color: #008080;">if</span> <span style="color: #000000;">c</span><span style="color: #0000FF;">=</span><span style="color: #004600;">K_ESC</span> <span style="color: #008080;">then</span> <span style="color: #008080;">return</span> <span style="color: #004600;">IUP_CLOSE</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
     <span style="color: #008080;">if</span> <span style="color: #000000;">c</span><span style="color: #0000FF;">=</span><span style="color: #004600;">K_F1</span> <span style="color: #008080;">then</span> <span style="color: #008080;">return</span> <span style="color: #000000;">help</span><span style="color: #0000FF;">()</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
     <span style="color: #008080;">if</span> <span style="color: #000000;">c</span><span style="color: #0000FF;">=</span><span style="color: #008000;">'+'</span> <span style="color: #008080;">then</span> <span style="color: #000000;">n</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">1</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
     <span style="color: #008080;">if</span> <span style="color: #000000;">c</span><span style="color: #0000FF;">=</span><span style="color: #008000;">'-'</span> <span style="color: #008080;">then</span> <span style="color: #000000;">n</span> <span style="color: #0000FF;">-=</span> <span style="color: #0000FF;">(</span><span style="color: #000000;">n</span><span style="color: #0000FF;">></span><span style="color: #000000;">1</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
     <span style="color: #000000;">c</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">upper</span><span style="color: #0000FF;">(</span><span style="color: #000000;">c</span><span style="color: #0000FF;">)</span>
     <span style="color: #008080;">if</span> <span style="color: #7060A8;">find</span><span style="color: #0000FF;">(</span><span style="color: #000000;">c</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"MOX"</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">then</span> <span style="color: #000000;">mtype</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">c</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
     <span style="color: #7060A8;">IupUpdate</span><span style="color: #0000FF;">(</span><span style="color: #000000;">canvas</span><span style="color: #0000FF;">)</span>
     <span style="color: #008080;">return</span> <span style="color: #004600;">IUP_CONTINUE</span>
 <span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
 
 <span style="color: #7060A8;">IupOpen</span><span style="color: #0000FF;">()</span>
 <span style="color: #000000;">canvas</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">IupCanvas</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"RASTERSIZE=532x532"</span><span style="color: #0000FF;">)</span>
 <span style="color: #7060A8;">IupSetCallback</span><span style="color: #0000FF;">(</span><span style="color: #000000;">canvas</span><span style="color: #0000FF;">,</span> <span style="color: #008000;">"MAP_CB"</span><span style="color: #0000FF;">,</span> <span style="color: #7060A8;">Icallback</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"map_cb"</span><span style="color: #0000FF;">))</span>
 <span style="color: #7060A8;">IupSetCallback</span><span style="color: #0000FF;">(</span><span style="color: #000000;">canvas</span><span style="color: #0000FF;">,</span> <span style="color: #008000;">"ACTION"</span><span style="color: #0000FF;">,</span> <span style="color: #7060A8;">Icallback</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"redraw_cb"</span><span style="color: #0000FF;">))</span>
 <span style="color: #000000;">dlg</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">IupDialog</span><span style="color: #0000FF;">(</span><span style="color: #000000;">canvas</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"MINSIZE=440x450"</span><span style="color: #0000FF;">)</span>
 <span style="color: #7060A8;">IupSetCallback</span><span style="color: #0000FF;">(</span><span style="color: #000000;">dlg</span><span style="color: #0000FF;">,</span> <span style="color: #008000;">"K_ANY"</span><span style="color: #0000FF;">,</span> <span style="color: #7060A8;">Icallback</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"key_cb"</span><span style="color: #0000FF;">))</span>
 <span style="color: #7060A8;">IupSetAttributeHandle</span><span style="color: #0000FF;">(</span><span style="color: #004600;">NULL</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"PARENTDIALOG"</span><span style="color: #0000FF;">,</span><span style="color: #000000;">dlg</span><span style="color: #0000FF;">)</span>
 <span style="color: #7060A8;">IupShow</span><span style="color: #0000FF;">(</span><span style="color: #000000;">dlg</span><span style="color: #0000FF;">)</span>
 <span style="color: #7060A8;">IupSetAttribute</span><span style="color: #0000FF;">(</span><span style="color: #000000;">canvas</span><span style="color: #0000FF;">,</span> <span style="color: #008000;">"RASTERSIZE"</span><span style="color: #0000FF;">,</span> <span style="color: #004600;">NULL</span><span style="color: #0000FF;">)</span>
 <span style="color: #008080;">if</span> <span style="color: #7060A8;">platform</span><span style="color: #0000FF;">()!=</span><span style="color: #004600;">JS</span> <span style="color: #008080;">then</span>
     <span style="color: #7060A8;">IupMainLoop</span><span style="color: #0000FF;">()</span>
     <span style="color: #7060A8;">IupClose</span><span style="color: #0000FF;">()</span>
 <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<!--</lang>-->

=={{header|PHP}}==
<lang php><?php

$n = 9; // the number of rows

for ($i = 1; $i <= $n; $i++) {
    for ($j = 1; $j <= $n; $j++) {
        echo ($i == $j || $i == $n - $j + 1) ? ' 1' : ' 0';
    }
    echo "\n";
}
</lang>
{{Output}}
<pre> 1 0 0 0 0 0 0 0 1
 0 1 0 0 0 0 0 1 0
 0 0 1 0 0 0 1 0 0
 0 0 0 1 0 1 0 0 0
 0 0 0 0 1 0 0 0 0
 0 0 0 1 0 1 0 0 0
 0 0 1 0 0 0 1 0 0
 0 1 0 0 0 0 0 1 0
 1 0 0 0 0 0 0 0 1
</pre>

=={{header|Python}}==
===Pure Python===
<lang python>'''Matrix with two diagonals'''


# twoDiagonalMatrix :: Int -> [[Int]]
def twoDiagonalMatrix(n):
    '''A square matrix of dimension n with ones
       along both diagonals, and zeros elsewhere.
    '''
    return matrix(
        n, n, lambda row, col: int(
            row in (col, 1 + (n - col))
        )
    )


# ------------------------- TEST -------------------------
# main :: IO ()
def main():
    '''Matrices of dimension 7 and 8'''
    for n in [7, 8]:
        print(
            showMatrix(
                twoDiagonalMatrix(n)
            ) + '\n'
        )


# ----------------------- GENERIC ------------------------

# matrix :: Int -> Int -> ((Int, Int) -> a) -> [[a]]
def matrix(nRows, nCols, f):
    '''A matrix of a given number of columns and rows,
       in which each value is a given function over the
       tuple of its (one-based) row and column indices.
    '''
    return [
        [f(y, x) for x in range(1, 1 + nCols)]
        for y in range(1, 1 + nRows)
    ]


# showMatrix :: [[Int]] -> String
def showMatrix(rows):
    '''String representation of a matrix'''
    return '\n'.join([
        ' '.join([str(x) for x in y]) for y in rows
    ])


# MAIN ---
if __name__ == '__main__':
    main()</lang>
{{Out}}
<pre>1 0 0 0 0 0 1
0 1 0 0 0 1 0
0 0 1 0 1 0 0
0 0 0 1 0 0 0
0 0 1 0 1 0 0
0 1 0 0 0 1 0
1 0 0 0 0 0 1

1 0 0 0 0 0 0 1
0 1 0 0 0 0 1 0
0 0 1 0 0 1 0 0
0 0 0 1 1 0 0 0
0 0 0 1 1 0 0 0
0 0 1 0 0 1 0 0
0 1 0 0 0 0 1 0
1 0 0 0 0 0 0 1</pre>

===NumPy===
{{libheader|numpy}}
<lang Python>import numpy as np

def diagdiag(n):
    """
    Create a diagonal-diagonal matrix

    Args:
        n (int): number of rows.

    Returns:
        a (numpy matrix): double diagonal matrix.
    """
    d = np.eye(n)
    a = d + np.fliplr(d)
    if n % 2:
        k = (n - 1) // 2
        a[k, k] = 1
    return a

print(diagdiag(7))</lang>
{{Output}}
<pre>
[[1. 0. 0. 0. 0. 0. 1.]
 [0. 1. 0. 0. 0. 1. 0.]
 [0. 0. 1. 0. 1. 0. 0.]
 [0. 0. 0. 1. 0. 0. 0.]
 [0. 0. 1. 0. 1. 0. 0.]
 [0. 1. 0. 0. 0. 1. 0.]
 [1. 0. 0. 0. 0. 0. 1.]]
</pre>

=={{header|Quackery}}==

<lang Quackery>  [ [] swap dup times
    [ 0 over of
      1 swap i poke
      1 swap i^ poke
      nested rot join swap ]
    drop ]                   is two-diagonals ( n --> [ )

  8 two-diagonals
  witheach
    [ witheach [ echo sp ] cr ]
  cr
  9 two-diagonals
  witheach
    [ witheach [ echo sp ] cr ]
</lang>

{{out}}

<pre>1 0 0 0 0 0 0 1 
0 1 0 0 0 0 1 0 
0 0 1 0 0 1 0 0 
0 0 0 1 1 0 0 0 
0 0 0 1 1 0 0 0 
0 0 1 0 0 1 0 0 
0 1 0 0 0 0 1 0 
1 0 0 0 0 0 0 1 

1 0 0 0 0 0 0 0 1 
0 1 0 0 0 0 0 1 0 
0 0 1 0 0 0 1 0 0 
0 0 0 1 0 1 0 0 0 
0 0 0 0 1 0 0 0 0 
0 0 0 1 0 1 0 0 0 
0 0 1 0 0 0 1 0 0 
0 1 0 0 0 0 0 1 0 
1 0 0 0 0 0 0 0 1 
</pre>

=={{header|Raku}}==
<lang perl6>sub dual-diagonal($n) { ([1, |(0 xx $n-1)], *.rotate(-1) … *[*-1]).map: { [$_ Z|| .reverse] } }

.say for dual-diagonal(6);
say '';
.say for dual-diagonal(7);</lang>
{{out}}
<pre>[1 0 0 0 0 1]
[0 1 0 0 1 0]
[0 0 1 1 0 0]
[0 0 1 1 0 0]
[0 1 0 0 1 0]
[1 0 0 0 0 1]

[1 0 0 0 0 0 1]
[0 1 0 0 0 1 0]
[0 0 1 0 1 0 0]
[0 0 0 1 0 0 0]
[0 0 1 0 1 0 0]
[0 1 0 0 0 1 0]
[1 0 0 0 0 0 1]</pre>

=={{header|Red}}==
<lang rebol>Red[]

x-matrix: function [size][
    repeat i size [
        repeat j size [
            prin either any [i = j i + j = (size + 1)] [1] [0]
            prin sp
        ]
        prin newline
    ]
]

x-matrix 6
prin newline
x-matrix 7</lang>
{{out}}
<pre>
1 0 0 0 0 1 
0 1 0 0 1 0 
0 0 1 1 0 0 
0 0 1 1 0 0 
0 1 0 0 1 0 
1 0 0 0 0 1 

1 0 0 0 0 0 1 
0 1 0 0 0 1 0 
0 0 1 0 1 0 0 
0 0 0 1 0 0 0 
0 0 1 0 1 0 0 
0 1 0 0 0 1 0 
1 0 0 0 0 0 1 
</pre>

=={{header|Ring}}==
<lang ring>
# Project : Identity Matrix
# Date    : 2022/16/02
# Author  : Gal Zsolt (~ CalmoSoft ~)
# Email   : <calmosoft@gmail.com>

load "stdlib.ring"
load "guilib.ring"

size = 8
C_Spacing = 1

C_ButtonBlueStyle   = 'border-radius:6px;color:black; background-color: blue'
C_ButtonOrangeStyle = 'border-radius:6px;color:black; background-color: orange'

Button = newlist(size,size)
LayoutButtonRow = list(size)

app = new qApp 
{
      win = new qWidget() {
	    setWindowTitle('Identity Matrix')
	    move(500,100)
	    reSize(600,600)
	    winheight = win.height()
	    fontSize = 18 + (winheight / 100)

 	    LayoutButtonMain = new QVBoxLayout()			
	    LayoutButtonMain.setSpacing(C_Spacing)
	    LayoutButtonMain.setContentsmargins(0,0,0,0)

	    for Row = 1 to size
		LayoutButtonRow[Row] = new QHBoxLayout() {
				       setSpacing(C_Spacing)
				       setContentsmargins(0,0,0,0)
				       } 
         	 for Col = 1 to size
		     Button[Row][Col] = new QPushButton(win) {
                                        setSizePolicy(1,1)                                                
					}
					
		     LayoutButtonRow[Row].AddWidget(Button[Row][Col])	
		 next
		 LayoutButtonMain.AddLayout(LayoutButtonRow[Row])			
	      next
              LayoutDataRow1 = new QHBoxLayout() { setSpacing(C_Spacing) setContentsMargins(0,0,0,0) }
              LayoutButtonMain.AddLayout(LayoutDataRow1)
              setLayout(LayoutButtonMain)
              show()
   }
   pBegin()
   exec()
   }

func pBegin()
     for Row = 1 to size
         for Col = 1 to size 
             if Row = Col or Row + Col = 9
                Button[Row][Col].setStyleSheet(C_ButtonOrangeStyle)
                Button[Row][Col].settext("1")
             else
                Button[Row][Col].setStyleSheet(C_ButtonBlueStyle)
                Button[Row][Col].settext("0")
             ok
	 next
     next
     score = 0
</lang>
Outpu image:
<br>
[http://keptarhely.eu/view.php?file=20220217v00xdle18.jpeg Special identity matrix with two diagonals]

=={{header|Sidef}}==
<lang ruby>func dual_diagonal(n) {
    n.of {|k|
        var r = (k.of(0) + [1] + (n - k - 1).of(0))
        r ~Z| r.reverse
    }
}

dual_diagonal(5).each{.join(' ').say}; say ''
dual_diagonal(6).each{.join(' ').say}</lang>
{{out}}
<pre>
1 0 0 0 1
0 1 0 1 0
0 0 1 0 0
0 1 0 1 0
1 0 0 0 1

1 0 0 0 0 1
0 1 0 0 1 0
0 0 1 1 0 0
0 0 1 1 0 0
0 1 0 0 1 0
1 0 0 0 0 1
</pre>

=={{header|Wren}}==
A terminal based solution as I don't like asking people to view external images.
<lang ecmascript>var specialMatrix = Fn.new { |n|
    for (i in 0...n) {
        for (j in 0...n) {
            System.write((i == j || i + j == n - 1) ? "1 " : "0 ")
        }
        System.print()
    }
}

specialMatrix.call(6)  // even n
System.print()
specialMatrix.call(7)  // odd n</lang>

{{out}}
<pre>
1 0 0 0 0 1 
0 1 0 0 1 0 
0 0 1 1 0 0 
0 0 1 1 0 0 
0 1 0 0 1 0 
1 0 0 0 0 1 

1 0 0 0 0 0 1 
0 1 0 0 0 1 0 
0 0 1 0 1 0 0 
0 0 0 1 0 0 0 
0 0 1 0 1 0 0 
0 1 0 0 0 1 0 
1 0 0 0 0 0 1 
</pre>

=={{header|XPL0}}==
<lang XPL0>proc DrawMat(S);
int  S, I, J;
[for I:= 0 to S-1 do
    [for J:= 0 to S-1 do
        Text(0, if J=I or J=S-1-I then "1 " else "0 ");
    CrLf(0);
    ];
];
[DrawMat(6);  CrLf(0);
 DrawMat(7);  CrLf(0);
]</lang>

{{out}}
<pre>
1 0 0 0 0 1 
0 1 0 0 1 0 
0 0 1 1 0 0 
0 0 1 1 0 0 
0 1 0 0 1 0 
1 0 0 0 0 1 

1 0 0 0 0 0 1 
0 1 0 0 0 1 0 
0 0 1 0 1 0 0 
0 0 0 1 0 0 0 
0 0 1 0 1 0 0 
0 1 0 0 0 1 0 
1 0 0 0 0 0 1 
</pre>