Fivenum

From Rosetta Code
Task
Fivenum
You are encouraged to solve this task according to the task description, using any language you may know.

Many big data or scientific programs use boxplots to show distributions of data.   In addition, sometimes saving large arrays for boxplots can be impractical and use extreme amounts of RAM.   It can be useful to save large arrays as arrays with five numbers to save memory.

For example, the   R   programming language implements Tukey's five-number summary as the fivenum function.


Task

Given an array of numbers, compute the five-number summary.


Note

While these five numbers can be used to draw a boxplot,   statistical packages will typically need extra data.

Moreover, while there is a consensus about the "box" of the boxplot,   there are variations among statistical packages for the whiskers.

11l

Translation of: Python
F fivenum(array)
   V n = array.len
   V x = sorted(array)
   V n4 = floor((n + 3.0) / 2.0) / 2.0
   V d = [1.0, n4, (n + 1) / 2, n + 1 - n4, Float(n)]
   [Float] sum_array
   L(e) 5
      V fl = Int(floor(d[e] - 1))
      V ce = Int(ceil(d[e] - 1))
      sum_array.append(0.5 * (x[fl] + x[ce]))
   R sum_array

V x = [0.14082834,  0.09748790, 1.73131507, 0.87636009, -1.95059594,  0.73438555, -0.03035726, 1.46675970,
      -0.74621349, -0.72588772, 0.63905160, 0.61501527, -0.98983780, -1.00447874, -0.62759469, 0.66206163,
       1.04312009, -0.10305385, 0.75775634, 0.32566578]

print(fivenum(x))
Output:
[-1.9506, -0.676741, 0.233247, 0.746071, 1.73132]

Ada

Direct C Translation

Translation of: C
with Ada.Text_IO; use Ada.Text_IO;
with Ada.Containers.Generic_Array_Sort;

procedure Main is
   package Real_Io is new Float_IO (Long_Float);
   use Real_Io;

   type Data_Array is array (Natural range <>) of Long_Float;
   subtype Five_Num_Type is Data_Array (0 .. 4);

   procedure Sort is new Ada.Containers.Generic_Array_Sort
     (Index_Type => Natural, Element_Type => Long_Float,
      Array_Type => Data_Array);

   function Median (X : Data_Array) return Long_Float with
      Pre => X'Length > 0;

   function Median (X : Data_Array) return Long_Float is
      M : constant Natural := X'First + X'Last / 2;
   begin
      if X'Length rem 2 = 1 then
         return X (M);
      else
         return (X (M - 1) + X (M)) / 2.0;
      end if;
   end Median;

   procedure fivenum (X : Data_Array; Result : out Five_Num_Type) is
      Temp      : Data_Array := X;
      m         : Natural    := X'Length / 2;
      Lower_end : Natural    := (if X'Length rem 2 = 0 then m - 1 else m);
   begin
      Sort (Temp);
      Result (0) := Temp (Temp'First);
      Result (2) := Median (Temp);
      Result (4) := Temp (Temp'Last);
      Result (1) := Median (Temp (1 .. Lower_end));
      Result (3) := Median (Temp (m .. Temp'Last));
   end fivenum;

   procedure print (Result : Five_Num_Type; Aft : Natural) is
   begin
      Put ("[");
      for I in Result'Range loop
         Put (Item => Result (I), Fore => 1, Aft => Aft, Exp => 0);
         if I < Result'Last then
            Put (", ");
         else
            Put_Line ("]");
         end if;
      end loop;
      New_Line;
   end print;

   X1 : Data_Array :=
     (15.0, 6.0, 42.0, 41.0, 7.0, 36.0, 49.0, 40.0, 39.0, 47.0, 43.0);
   X2 : Data_Array := (36.0, 40.0, 7.0, 39.0, 41.0, 15.0);
   X3 : Data_Array :=
     (0.140_828_34, 0.097_487_90, 1.731_315_07, 0.876_360_09, -1.950_595_94,
      0.734_385_55, -0.030_357_26, 1.466_759_70, -0.746_213_49, -0.725_887_72,
      0.639_051_60, 0.615_015_27, -0.989_837_80, -1.004_478_74, -0.627_594_69,
      0.662_061_63, 1.043_120_09, -0.103_053_85, 0.757_756_34, 0.325_665_78);
   Result : Five_Num_Type;
begin
   fivenum (X1, Result);
   print (Result, 1);
   fivenum (X2, Result);
   print (Result, 1);
   fivenum (X3, Result);
   print (Result, 9);
end Main;
Output:
[6.0, 36.0, 40.0, 48.0, 49.0]

[7.0, 25.5, 25.5, 41.0, 41.0]

[-1.950595940, -0.627594690, 0.119158120, 1.599037385, 1.731315070]

Using Ada Enumeration

with Ada.Text_IO; use Ada.Text_IO;
with Ada.Containers.Generic_Array_Sort;

procedure Main is
   package Real_Io is new Float_IO (Long_Float);
   use Real_Io;

   type Data_Array is array (Natural range <>) of Long_Float;

   type fivenum_index is (minimum, lower_hinge, median, upper_hinge, maximum);
   type Five_Num_Type is array (fivenum_index) of Long_Float;

   procedure Sort is new Ada.Containers.Generic_Array_Sort
     (Index_Type => Natural, Element_Type => Long_Float,
      Array_Type => Data_Array);

   function Median (X : Data_Array) return Long_Float with
      Pre => X'Length > 0;

   function Median (X : Data_Array) return Long_Float is
      M : constant Natural := X'First + X'Last / 2;
   begin
      if X'Length rem 2 = 1 then
         return X (M);
      else
         return (X (M - 1) + X (M)) / 2.0;
      end if;
   end Median;

   procedure fivenum (X : Data_Array; Result : out Five_Num_Type) is
      Temp      : Data_Array := X;
      m         : Natural    := X'Length / 2;
      Lower_end : Natural    := (if X'Length rem 2 = 0 then m - 1 else m);
   begin
      Sort (Temp);
      Result (minimum)     := Temp (Temp'First);
      Result (lower_hinge) := Median (Temp (0 .. Lower_end));
      Result (median)      := Median (Temp);
      Result (upper_hinge) := Median (Temp (m .. Temp'Last));
      Result (maximum)     := Temp (Temp'Last);
   end fivenum;

   procedure print (Result : Five_Num_Type) is
      package five_io is new Enumeration_IO (fivenum_index);
      use five_io;
   begin
      for I in fivenum_index loop
         Put("   ");
         Put (Item => I, Width => 12);
      end loop;
      New_Line;
      Put ("[");
      for I in Result'Range loop
         Put (Item => Result (I), Fore => 3, Aft => 9, Exp => 0);
         if I < Result'Last then
            Put (", ");
         else
            Put_Line ("]");
         end if;
      end loop;
      New_Line;
   end print;

   X1 : Data_Array :=
     (15.0, 6.0, 42.0, 41.0, 7.0, 36.0, 49.0, 40.0, 39.0, 47.0, 43.0);
   X2 : Data_Array := (36.0, 40.0, 7.0, 39.0, 41.0, 15.0);
   X3 : Data_Array :=
     (0.140_828_34, 0.097_487_90, 1.731_315_07, 0.876_360_09, -1.950_595_94,
      0.734_385_55, -0.030_357_26, 1.466_759_70, -0.746_213_49, -0.725_887_72,
      0.639_051_60, 0.615_015_27, -0.989_837_80, -1.004_478_74, -0.627_594_69,
      0.662_061_63, 1.043_120_09, -0.103_053_85, 0.757_756_34, 0.325_665_78);
   Result : Five_Num_Type;
begin
   fivenum (X1, Result);
   print (Result);
   fivenum (X2, Result);
   print (Result);
   fivenum (X3, Result);
   print (Result);
end Main;
Output:
   MINIMUM        LOWER_HINGE    MEDIAN         UPPER_HINGE    MAXIMUM     
[  6.000000000,  11.000000000,  40.000000000,  48.000000000,  49.000000000]

   MINIMUM        LOWER_HINGE    MEDIAN         UPPER_HINGE    MAXIMUM     
[  7.000000000,  15.000000000,  25.500000000,  41.000000000,  41.000000000]

   MINIMUM        LOWER_HINGE    MEDIAN         UPPER_HINGE    MAXIMUM     
[ -1.950595940,  -0.736050605,   0.119158120,   1.599037385,   1.731315070]

ALGOL 68

Translation of: 11l

Includes additional test cases and adjustment to n4 for odd length array as in a number of other samples.

Library: ALGOL 68-rows
BEGIN # construct an R-style fivenum function #
    PR read "rows.incl.a68" PR

    PROC fivenum = ( []REAL array )[]REAL:
         BEGIN
            INT n = ( UPB array + 1 ) - LWB array;
            [ 1 : n ]REAL x := array[ AT 1 ];
            QUICKSORT x FROMELEMENT LWB x TOELEMENT UPB x;
            REAL   n4 = ( ( ( n + IF ODD n THEN 3 ELSE 2 FI ) / 2 ) / 2 ) ;
            []REAL d  = ( 1, n4, ( n + 1 ) / 2, n + 1 - n4, n );
            [ 1 : 5 ]REAL sum_array;
            FOR e TO 5 DO
                INT fl = ENTIER d[ e ];
                INT ce = IF fl < d[ e ] THEN 1 + fl ELSE fl FI;
                sum_array[ e ] := 0.5 * ( x[ fl ] + x[ ce ] )
            OD;
            sum_array
         END # five num # ;

    SHOW fivenum( ( 36, 40, 7, 39, 41, 15 ) );
    print( ( newline ) );
    SHOW fivenum( ( 15, 6, 42, 41, 7, 36, 49, 40, 39, 47, 43 ) );
    print( ( newline ) );
    SHOW fivenum( (  0.14082834,  0.09748790,  1.73131507, 0.87636009
                  , -1.95059594,  0.73438555, -0.03035726, 1.46675970
                  , -0.74621349, -0.72588772,  0.63905160, 0.61501527
                  , -0.98983780, -1.00447874, -0.62759469, 0.66206163
                  ,  1.04312009, -0.10305385,  0.75775634, 0.32566578
                  )
                )
END
Output:
     7.00000000    15.00000000    37.50000000    40.00000000    41.00000000
     6.00000000    25.50000000    40.00000000    42.50000000    49.00000000
    -1.95059594    -0.67674120     0.23324706     0.74607095     1.73131507

AppleScript

use AppleScript version "2.4" -- Mac OS X 10.10. (Yosemite) or later.
use framework "Foundation"

on fivenum(listOfNumbers, l, r)
    script o
        property lst : missing value
        
        on medianFromRange(l, r)
            set m1 to (l + r) div 2
            set m2 to m1 + (l + r) mod 2
            set median to my lst's item m1
            if (m2 > m1) then set median to (median + (my lst's item m2)) / 2
            
            return {median, m1, m2}
        end medianFromRange
    end script
    
    if ((listOfNumbers is {}) or (r - l < 0)) then return missing value
    set o's lst to current application's class "NSMutableArray"'s arrayWithArray:(listOfNumbers)
    tell o's lst to sortUsingSelector:("compare:")
    set o's lst to o's lst as list
    
    set {median, m1, m2} to o's medianFromRange(l, r)
    set {lowerQuartile} to o's medianFromRange(l, m1)
    set {upperQuartile} to o's medianFromRange(m2, r)
    
    return {o's lst's beginning, lowerQuartile, median, upperQuartile, o's lst's end}
end fivenum

-- Test code:
set x to {15, 6, 42, 41, 7, 36, 49, 40, 39, 47, 43}
set y to {36, 40, 7, 39, 41, 15}
set z to {0.14082834, 0.0974879, 1.73131507, 0.87636009, -1.95059594, 0.73438555, -0.03035726, 1.4667597, -0.74621349, -0.72588772, ¬
    0.6390516, 0.61501527, -0.9898378, -1.00447874, -0.62759469, 0.66206163, 1.04312009, -0.10305385, 0.75775634, 0.32566578}
return {fivenum(x, 1, count x), fivenum(y, 1, count y), fivenum(z, 1, count z)}
Output:
{{6, 25.5, 40, 42.5, 49}, {7, 15, 37.5, 40, 41}, {-1.95059594, -0.676741205, 0.23324706, 0.746070945, 1.73131507}}

Arturo

fivenum: function [lst][
    lst: sort lst
    m: (size lst)/2
    lowerEnd: (odd? size lst)? -> m -> m-1

    return @[
        first lst
        median slice lst 0 lowerEnd
        median slice lst 0 dec size lst
        median slice lst m dec size lst
        last lst
    ]
]

lists: @[
    @[15.0, 6.0, 42.0, 41.0, 7.0, 36.0, 49.0, 40.0, 39.0, 47.0, 43.0],
    @[36.0, 40.0, 7.0, 39.0, 41.0, 15.0],
    @[0.14082834,  0.09748790,  1.73131507,  0.87636009,0-1.95059594,
      0.73438555,0-0.03035726,  1.46675970,0-0.74621349,0-0.72588772,
      0.63905160,  0.61501527,0-0.98983780,0-1.00447874,0-0.62759469,
      0.66206163,  1.04312009,0-0.10305385,  0.75775634,  0.32566578]
]

loop lists 'l [
    print [l "->"]
    print [fivenum l]
    print ""
]
Output:
[15.0 6.0 42.0 41.0 7.0 36.0 49.0 40.0 39.0 47.0 43.0] -> 
[6.0 25.5 40.0 42.5 49.0] 

[36.0 40.0 7.0 39.0 41.0 15.0] -> 
[7.0 15.0 37.5 40.0 41.0] 

[0.14082834 0.0974879 1.73131507 0.87636009 -1.95059594 0.7343855500000001 -0.03035726 1.4667597 -0.74621349 -0.72588772 0.6390516000000001 0.61501527 -0.9898378 -1.00447874 -0.62759469 0.66206163 1.04312009 -0.10305385 0.75775634 0.32566578] -> 
[-1.95059594 -0.676741205 0.23324706 0.746070945 1.73131507]

BASIC

FreeBASIC

Translation of: Phix
#define floor(x) ((x*2.0-0.5) Shr 1)

Sub rapidSort (array()As Single, l As Integer, r As Integer)
    Dim As Integer n, wert, nptr, rep
    Dim As Single arr, LoVal = array(l), HiVal = array(r)
    For n = l To r
        If LoVal > array(n) Then LoVal = array(n)
        If HiVal < array(n) Then HiVal = array(n)
    Next n
    Redim SortArray(LoVal To HiVal) As Single
    For n = l To r
        wert = array(n)
        SortArray(wert) += 1
    Next n
    nptr = l-1
    For arr = LoVal To HiVal
        rep = SortArray(arr)
        For n = 1 To rep
            nptr += 1
            array(nptr) = arr
        Next n
    Next arr
    Erase SortArray
End Sub

Function median(tbl() As Single, lo As Integer, hi As Integer) As Single
    Dim As Integer l = hi-lo+1
    Dim As Integer m = lo+floor(l/2)
    
    If l Mod 2 = 1 Then Return tbl(m)
    Return (tbl(m-1)+tbl(m))/2
End Function

Sub fivenum(tbl() As Single)
    rapidSort(tbl(), Lbound(tbl), Ubound(tbl))
    Dim As Integer l = Ubound(tbl)
    Dim As Single m = floor(l/2) + (l Mod 2)
    Dim As Single r1,r2,r3,r4,r5
    
    r1 = tbl(1)
    r2 = median(tbl(),1,m)
    r3 = median(tbl(),1,l)
    r4 = median(tbl(),m+1,l)
    r5 = tbl(l)
    
    Print "[" & r1; ","; r2; ","; r3; ","; r4; ", "; r5 & "]"
End Sub

Dim As Single x1(1 To ...) = {15, 6, 42, 41, 7, 36, 49, 40, 39, 47, 43}
Dim As Single x2(1 To ...) = {36, 40, 7, 39, 41, 15}
Dim As Single x3(1 To ...) = {_
0.14082834,  0.09748790,  1.73131507,  0.87636009, -1.95059594, _
0.73438555, -0.03035726,  1.46675970, -0.74621349, -0.72588772, _
0.63905160,  0.61501527, -0.98983780, -1.00447874, -0.62759469, _
0.66206163,  1.04312009, -0.10305385,  0.75775634,  0.32566578}
fivenum(x1())
fivenum(x2())
fivenum(x3())

Sleep
Output:
[6, 25.5, 40, 43, 49]
[7, 15, 37.5, 40, 41]
[-1.950596,-0.950596, 0.04940403, 1.049404, 0.3256658]

VBA

Uses Quicksort.

Translation of: Phix
Option Base 1
Private Function median(tbl As Variant, lo As Integer, hi As Integer)
    Dim l As Integer: l = hi - lo + 1
    Dim m As Integer: m = lo + WorksheetFunction.Floor_Precise(l / 2)
    If l Mod 2 = 1 Then
        median = tbl(m)
    Else
        median = (tbl(m - 1) + tbl(m)) / 2
    End if 
End Function
Private Function fivenum(tbl As Variant) As Variant
    Sort tbl, UBound(tbl)
    Dim l As Integer: l = UBound(tbl)
    Dim m As Integer: m = WorksheetFunction.Floor_Precise(l / 2) + l Mod 2
    Dim r(5) As String
    r(1) = CStr(tbl(1))
    r(2) = CStr(median(tbl, 1, m))
    r(3) = CStr(median(tbl, 1, l))
    r(4) = CStr(median(tbl, m + 1, l))
    r(5) = CStr(tbl(l))
    fivenum = r
End Function
Public Sub main()
    Dim x1 As Variant, x2 As Variant, x3 As Variant
    x1 = [{15, 6, 42, 41, 7, 36, 49, 40, 39, 47, 43}]
    x2 = [{36, 40, 7, 39, 41, 15}]
    x3 = [{0.14082834, 0.09748790, 1.73131507, 0.87636009, -1.95059594, 0.73438555, -0.03035726, 1.46675970, -0.74621349, -0.72588772, 0.63905160, 0.61501527, -0.98983780, -1.00447874, -0.62759469, 0.66206163, 1.04312009, -0.10305385, 0.75775634, 0.32566578}]
    Debug.Print Join(fivenum(x1), " | ")
    Debug.Print Join(fivenum(x2), " | ")
    Debug.Print Join(fivenum(x3), " | ")
End Sub
Output:
6 | 25,5 | 40 | 43 | 49
7 | 15 | 37,5 | 40 | 41
-1,95059594 | -0,676741205 | 0,23324706 | 0,746070945 | 1,73131507

Visual Basic .NET

Translation of: C#
Imports System.Runtime.CompilerServices
Imports System.Text

Module Module1

    <Extension()>
    Function AsString(Of T)(c As ICollection(Of T), Optional format As String = "{0}") As String
        Dim sb As New StringBuilder("[")
        Dim it = c.GetEnumerator()
        If it.MoveNext() Then
            sb.AppendFormat(format, it.Current)
        End If
        While it.MoveNext()
            sb.Append(", ")
            sb.AppendFormat(format, it.Current)
        End While
        Return sb.Append("]").ToString()
    End Function

    Function Median(x As Double(), start As Integer, endInclusive As Integer) As Double
        Dim size = endInclusive - start + 1
        If size <= 0 Then
            Throw New ArgumentException("Array slice cannot be empty")
        End If
        Dim m = start + size \ 2
        Return If(size Mod 2 = 1, x(m), (x(m - 1) + x(m)) / 2.0)
    End Function

    Function Fivenum(x As Double()) As Double()
        For Each d In x
            If Double.IsNaN(d) Then
                Throw New ArgumentException("Unable to deal with arrays containing NaN")
            End If
        Next

        Array.Sort(x)
        Dim result(4) As Double

        result(0) = x.First()
        result(2) = Median(x, 0, x.Length - 1)
        result(4) = x.Last()

        Dim m = x.Length \ 2
        Dim lowerEnd = If(x.Length Mod 2 = 1, m, m - 1)

        result(1) = Median(x, 0, lowerEnd)
        result(3) = Median(x, m, x.Length - 1)

        Return result
    End Function

    Sub Main()
        Dim x1 = {
            New Double() {15.0, 6.0, 42.0, 41.0, 7.0, 36.0, 49.0, 40.0, 39.0, 47.0, 43.0},
            New Double() {36.0, 40.0, 7.0, 39.0, 41.0, 15.0},
            New Double() {
                     0.14082834, 0.0974879, 1.73131507, 0.87636009, -1.95059594, 0.73438555,
                    -0.03035726, 1.4667597, -0.74621349, -0.72588772, 0.6390516, 0.61501527,
                    -0.9898378, -1.00447874, -0.62759469, 0.66206163, 1.04312009, -0.10305385,
                     0.75775634, 0.32566578
            }
        }
        For Each x In x1
            Dim result = Fivenum(x)
            Console.WriteLine(result.AsString("{0:F8}"))
        Next
    End Sub

End Module
Output:
[6.00000000, 25.50000000, 40.00000000, 42.50000000, 49.00000000]
[7.00000000, 15.00000000, 37.50000000, 40.00000000, 41.00000000]
[-1.95059594, -0.67674121, 0.23324706, 0.74607095, 1.73131507]

C

Translation of: Kotlin
#include <stdio.h>
#include <stdlib.h>

double median(double *x, int start, int end_inclusive) {
    int size = end_inclusive - start + 1;
    if (size <= 0) {
        printf("Array slice cannot be empty\n");
        exit(1);
    }
    int m = start + size / 2;
    if (size % 2) return x[m];
    return (x[m - 1] + x[m]) / 2.0;
}

int compare (const void *a, const void *b) {
    double aa = *(double*)a; 
    double bb = *(double*)b;
    if (aa > bb) return 1;
    if (aa < bb) return -1;
    return 0;
}

int fivenum(double *x, double *result, int x_len) {
    int i, m, lower_end;
    for (i = 0; i < x_len; i++) {
        if (x[i] != x[i]) {
           printf("Unable to deal with arrays containing NaN\n\n");
           return 1;
        }
    } 
    qsort(x, x_len, sizeof(double), compare);
    result[0] = x[0];
    result[2] = median(x, 0, x_len - 1);
    result[4] = x[x_len - 1];
    m = x_len / 2;
    lower_end = (x_len % 2) ? m : m - 1;
    result[1] = median(x, 0, lower_end);
    result[3] = median(x, m, x_len - 1);
    return 0;
}

int show(double *result, int places) {
    int i;
    char f[7];
    sprintf(f, "%%.%dlf", places);
    printf("[");
    for (i = 0; i < 5; i++) {     
        printf(f, result[i]);
        if (i < 4) printf(", ");
    }
    printf("]\n\n");
}

int main() {
    double result[5];

    double x1[11] = {15.0, 6.0, 42.0, 41.0, 7.0, 36.0, 49.0, 40.0, 39.0, 47.0, 43.0};
    if (!fivenum(x1, result, 11)) show(result, 1);

    double x2[6] = {36.0, 40.0, 7.0, 39.0, 41.0, 15.0};
    if (!fivenum(x2, result, 6)) show(result, 1);

    double x3[20] = {
         0.14082834,  0.09748790,  1.73131507,  0.87636009, -1.95059594,  0.73438555,
        -0.03035726,  1.46675970, -0.74621349, -0.72588772,  0.63905160,  0.61501527,
        -0.98983780, -1.00447874, -0.62759469,  0.66206163,  1.04312009, -0.10305385,
         0.75775634,  0.32566578
    };
    if (!fivenum(x3, result, 20)) show(result, 9);

    return 0;
}
Output:
[6.0, 25.5, 40.0, 42.5, 49.0]

[7.0, 15.0, 37.5, 40.0, 41.0]

[-1.950595940, -0.676741205, 0.233247060, 0.746070945, 1.731315070]

C#

Translation of: Java
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace Fivenum {
    public static class Helper {
        public static string AsString<T>(this ICollection<T> c, string format = "{0}") {
            StringBuilder sb = new StringBuilder("[");
            int count = 0;
            foreach (var t in c) {
                if (count++ > 0) {
                    sb.Append(", ");
                }
                sb.AppendFormat(format, t);
            }
            return sb.Append("]").ToString();
        }
    }

    class Program {
        static double Median(double[] x, int start, int endInclusive) {
            int size = endInclusive - start + 1;
            if (size <= 0) throw new ArgumentException("Array slice cannot be empty");
            int m = start + size / 2;
            return (size % 2 == 1) ? x[m] : (x[m - 1] + x[m]) / 2.0;
        }

        static double[] Fivenum(double[] x) {
            foreach (var d in x) {
                if (Double.IsNaN(d)) {
                    throw new ArgumentException("Unable to deal with arrays containing NaN");
                }
            }
            double[] result = new double[5];
            Array.Sort(x);
            result[0] = x.First();
            result[2] = Median(x, 0, x.Length - 1);
            result[4] = x.Last();
            int m = x.Length / 2;
            int lowerEnd = (x.Length % 2 == 1) ? m : m - 1;
            result[1] = Median(x, 0, lowerEnd);
            result[3] = Median(x, m, x.Length - 1);
            return result;
        }

        static void Main(string[] args) {
            double[][] x1 = new double[][]{
                new double[]{ 15.0, 6.0, 42.0, 41.0, 7.0, 36.0, 49.0, 40.0, 39.0, 47.0, 43.0},
                new double[]{ 36.0, 40.0, 7.0, 39.0, 41.0, 15.0},
                new double[]{
                     0.14082834,  0.09748790,  1.73131507,  0.87636009, -1.95059594,  0.73438555,
                    -0.03035726,  1.46675970, -0.74621349, -0.72588772,  0.63905160,  0.61501527,
                    -0.98983780, -1.00447874, -0.62759469,  0.66206163,  1.04312009, -0.10305385,
                     0.75775634,  0.32566578
                },
            };
            foreach(var x in x1) {
                var result = Fivenum(x);
                Console.WriteLine(result.AsString("{0:F8}"));
            }
        }
    }
}
Output:
[6.00000000, 25.50000000, 40.00000000, 42.50000000, 49.00000000]
[7.00000000, 15.00000000, 37.50000000, 40.00000000, 41.00000000]
[-1.95059594, -0.67674121, 0.23324706, 0.74607095, 1.73131507]

C++

Translation of: D
#include <algorithm>
#include <iostream>
#include <ostream>
#include <vector>

/////////////////////////////////////////////////////////////////////////////
// The following is taken from https://cpplove.blogspot.com/2012/07/printing-tuples.html

// Define a type which holds an unsigned integer value 
template<std::size_t> struct int_ {};

template <class Tuple, size_t Pos>
std::ostream& print_tuple(std::ostream& out, const Tuple& t, int_<Pos>) {
    out << std::get< std::tuple_size<Tuple>::value - Pos >(t) << ", ";
    return print_tuple(out, t, int_<Pos - 1>());
}

template <class Tuple>
std::ostream& print_tuple(std::ostream& out, const Tuple& t, int_<1>) {
    return out << std::get<std::tuple_size<Tuple>::value - 1>(t);
}

template <class... Args>
std::ostream& operator<<(std::ostream& out, const std::tuple<Args...>& t) {
    out << '(';
    print_tuple(out, t, int_<sizeof...(Args)>());
    return out << ')';
}

/////////////////////////////////////////////////////////////////////////////

template <class RI>
double median(RI beg, RI end) {
    if (beg == end) throw std::runtime_error("Range cannot be empty");
    auto len = end - beg;
    auto m = len / 2;
    if (len % 2 == 1) {
        return *(beg + m);
    }

    return (beg[m - 1] + beg[m]) / 2.0;
}

template <class C>
auto fivenum(C& c) {
    std::sort(c.begin(), c.end());

    auto cbeg = c.cbegin();
    auto cend = c.cend();

    auto len = cend - cbeg;
    auto m = len / 2;
    auto lower = (len % 2 == 1) ? m : m - 1;
    double r2 = median(cbeg, cbeg + lower + 1);
    double r3 = median(cbeg, cend);
    double r4 = median(cbeg + lower + 1, cend);

    return std::make_tuple(*cbeg, r2, r3, r4, *(cend - 1));
}

int main() {
    using namespace std;
    vector<vector<double>> cs = {
        { 15.0, 6.0, 42.0, 41.0, 7.0, 36.0, 49.0, 40.0, 39.0, 47.0, 43.0 },
        { 36.0, 40.0, 7.0, 39.0, 41.0, 15.0 },
        {
            0.14082834,  0.09748790,  1.73131507,  0.87636009, -1.95059594,  0.73438555,
           -0.03035726,  1.46675970, -0.74621349, -0.72588772,  0.63905160,  0.61501527,
           -0.98983780, -1.00447874, -0.62759469,  0.66206163,  1.04312009, -0.10305385,
            0.75775634,  0.32566578
        }
    };

    for (auto & c : cs) {
        cout << fivenum(c) << endl;
    }

    return 0;
}
Output:
(6, 25.5, 40, 43, 49)
(7, 15, 37.5, 40, 41)
(-1.9506, -0.676741, 0.233247, 0.746071, 1.73132)

D

Translation of: Java
import std.algorithm;
import std.exception;
import std.math;
import std.stdio;

double median(double[] x) {
    enforce(x.length >= 0, "Array slice cannot be empty");
    int m = x.length / 2;
    if (x.length % 2 == 1) {
        return x[m];
    }
    return (x[m-1] + x[m]) / 2.0;
}

double[] fivenum(double[] x) {
    foreach (d; x) {
        enforce(!d.isNaN, "Unable to deal with arrays containing NaN");
    }

    double[] result;
    result.length = 5;

    x.sort;
    result[0] = x[0];
    result[2] = median(x);
    result[4] = x[$-1];

    int m = x.length / 2;
    int lower = (x.length % 2 == 1) ? m : m - 1;
    result[1] = median(x[0..lower+1]);
    result[3] = median(x[lower+1..$]);

    return result;
}

void main() {
    double[][] x1 = [
        [15.0, 6.0, 42.0, 41.0, 7.0, 36.0, 49.0, 40.0, 39.0, 47.0, 43.0],
        [36.0, 40.0, 7.0, 39.0, 41.0, 15.0],
        [
            0.14082834,  0.09748790,  1.73131507,  0.87636009, -1.95059594,  0.73438555,
           -0.03035726,  1.46675970, -0.74621349, -0.72588772,  0.63905160,  0.61501527,
           -0.98983780, -1.00447874, -0.62759469,  0.66206163,  1.04312009, -0.10305385,
            0.75775634,  0.32566578
        ]
    ];
    foreach(x; x1) {
        writeln(fivenum(x));
    }
}
Output:
[6, 25.5, 40, 43, 49]
[7, 15, 37.5, 40, 41]
[-1.9506, -0.676741, 0.233247, 0.746071, 1.73132]

Delphi

Translation of: Java
program Fivenum;

{$APPTYPE CONSOLE}

uses
  System.SysUtils,
  System.Generics.Collections;

function Median(x: TArray<Double>; start, endInclusive: Integer): Double;
var
  size, m: Integer;
begin
  size := endInclusive - start + 1;
  if (size <= 0) then
    raise EArgumentException.Create('Array slice cannot be empty');
  m := start + size div 2;
  if (odd(size)) then
    Result := x[m]
  else
    Result := (x[m - 1] + x[m]) / 2;
end;

function FiveNumber(x: TArray<Double>): TArray<Double>;
var
  m, lowerEnd: Integer;
begin
  SetLength(result, 5);
  TArray.Sort<double>(x);
  result[0] := x[0];
  result[2] := median(x, 0, length(x) - 1);
  result[4] := x[length(x) - 1];
  m := length(x) div 2;
  if odd(length(x)) then
    lowerEnd := m
  else
    lowerEnd := m - 1;
  result[1] := median(x, 0, lowerEnd);
  result[3] := median(x, m, length(x) - 1);
end;

function ArrayToString(x: TArray<double>): string;
var
  i: Integer;
begin
  Result := '[';
  for i := 0 to High(x) do
  begin
    if i > 0 then
      Result := Result + ',';
    Result := Result + format('%.4f', [x[i]]);
  end;
  Result := Result + ']';
end;

var
  xl: array of TArray<double> = [[15.0, 6.0, 42.0, 41.0, 7.0, 36.0, 49.0, 40.0,
    39.0, 47.0, 43.0], [36.0, 40.0, 7.0, 39.0, 41.0, 15.0], [0.14082834,
    0.09748790, 1.73131507, 0.87636009, -1.95059594, 0.73438555, -0.03035726,
    1.46675970, -0.74621349, -0.72588772, 0.63905160, 0.61501527, -0.98983780, -
    1.00447874, -0.62759469, 0.66206163, 1.04312009, -0.10305385, 0.75775634,
    0.32566578]];
  x: TArray<double>;

begin
  for x in xl do
    writeln(ArrayToString(FiveNumber(x)), #10);

  readln;
end.
Output:
[6,0000,25,5000,40,0000,42,5000,49,0000]

[7,0000,15,0000,37,5000,40,0000,41,0000]

[-1,9506,-0,6767,0,2332,0,7461,1,7313]

EMal

Translation of: Java
type Fivenum
int ILLEGAL_ARGUMENT = 0
fun median = real by List x, int start, int endInclusive
  int size = endInclusive - start + 1
  if size <= 0 do Event.error(ILLEGAL_ARGUMENT, "Array slice cannot be empty").raise() end
  int m = start + size / 2
  return when(size % 2 == 1, x[m], (x[m - 1] + x[m]) / 2.0)
end
fun fivenum = List by List x
  List result = real[].with(5)
  x.order()
  result[0] = x[0]
  result[2] = median(x, 0, x.length - 1)
  result[4] = x[x.length - 1]
  int m = x.length / 2
  int lowerEnd = when(x.length % 2 == 1, m, m - 1)
  result[1] = median(x, 0, lowerEnd)
  result[3] = median(x, m, x.length - 1)
  return result
end
List lists = List[
  real[15.0, 6.0, 42.0, 41.0, 7.0, 36.0, 49.0, 40.0, 39.0, 47.0, 43.0],  
  real[36.0, 40.0, 7.0, 39.0, 41.0, 15.0],
  real[ 0.14082834,  0.09748790, 1.73131507, 0.87636009, -1.95059594, 0.73438555, 
       -0.03035726,  1.46675970, -0.74621349, -0.72588772,  0.63905160,
        0.61501527, -0.98983780, -1.00447874, -0.62759469,  0.66206163,  
        1.04312009, -0.10305385,  0.75775634,  0.32566578] ]
for each List list in lists
  writeLine(text!fivenum(list))
end
Output:
[6.0,25.5,40.0,42.5,49.0]
[7.0,15.0,37.5,40.0,41.0]
[-1.95059594,-0.676741205,0.23324706,0.746070945,1.73131507]

F#

Translation of: C#
open System

// Take from https://stackoverflow.com/a/1175123
let rec last = function
    | hd :: [] -> hd
    | _ :: tl -> last tl
    | _ -> failwith "Empty list."

let median x =
    for e in x do
        if Double.IsNaN(e) then failwith "unable to deal with lists containing NaN"

    let size = List.length(x)
    if size <= 0 then failwith "Array slice cannot be empty"
    let m = size / 2
    if size % 2 = 1 then x.[m]
    else (x.[m - 1] + x.[m]) / 2.0

let fivenum x =
    let x2 = List.sort(x)
    let m = List.length(x2) / 2
    let lowerEnd = if List.length(x2) % 2 = 1 then m else m - 1
    [List.head x2, median x2.[..lowerEnd], median x2, median x2.[m..], last x2]

[<EntryPoint>]
let main _ =
    let x1 = [
        [15.0; 6.0; 42.0; 41.0; 7.0; 36.0; 49.0; 40.0; 39.0; 47.0; 43.0];
        [36.0; 40.0; 7.0; 39.0; 41.0; 15.0];
        [
             0.14082834;  0.09748790;  1.73131507;  0.87636009; -1.95059594;
             0.73438555; -0.03035726;  1.46675970; -0.74621349; -0.72588772;
             0.63905160;  0.61501527; -0.98983780; -1.00447874; -0.62759469;
             0.66206163;  1.04312009; -0.10305385;  0.75775634;  0.32566578
        ]
    ]

    for a in x1 do
        let y = fivenum a
        Console.WriteLine("{0}", y);

    0 // return an integer exit code
Output:
[(6, 25.5, 40, 42.5, 49)]
[(7, 15, 37.5, 40, 41)]
[(-1.95059594, -0.676741205, 0.23324706, 0.746070945, 1.73131507)]

Factor

USING: combinators combinators.smart kernel math
math.statistics prettyprint sequences sorting ;
IN: rosetta-code.five-number

<PRIVATE

: bisect ( seq -- lower upper )
    dup length even? [ halves ]
    [ dup midpoint@ 1 + [ head ] [ tail* ] 2bi ] if ;

: (fivenum) ( seq -- summary )
    natural-sort {
        [ infimum ]
        [ bisect drop median ]
        [ median ]
        [ bisect nip median ]
        [ supremum ]
    } cleave>array ;

PRIVATE>

ERROR: fivenum-empty data ;
ERROR: fivenum-nan data ;

: fivenum ( seq -- summary )
    {
        { [ dup empty? ] [ fivenum-empty ] }
        { [ dup [ fp-nan? ] any? ] [ fivenum-nan ] }
        [ (fivenum) ]
    } cond ;

: fivenum-demo ( -- )
    { 15 6 42 41 7 36 49 40 39 47 43 }
    { 36 40 7 39 41 15 }
    {  0.14082834  0.09748790  1.73131507  0.87636009
      -1.95059594  0.73438555 -0.03035726  1.46675970
      -0.74621349 -0.72588772  0.63905160  0.61501527
      -0.98983780 -1.00447874 -0.62759469  0.66206163
       1.04312009 -0.10305385  0.75775634  0.32566578 }
    [ fivenum . ] tri@ ;

MAIN: fivenum-demo
Output:
{ 6 25+1/2 40 42+1/2 49 }
{ 7 15 37+1/2 40 41 }
{ -1.95059594 -0.676741205 0.23324706 0.746070945 1.73131507 }

Go

Translation of: Perl
package main

import (
    "fmt"
    "math"
    "sort"
)

func fivenum(a []float64) (n5 [5]float64) {
    sort.Float64s(a)
    n := float64(len(a))
    n4 := float64((len(a)+3)/2) / 2
    d := []float64{1, n4, (n + 1) / 2, n + 1 - n4, n}
    for e, de := range d {
        floor := int(de - 1)
        ceil := int(math.Ceil(de - 1))
        n5[e] = .5 * (a[floor] + a[ceil])
    }
    return
}

var (
    x1 = []float64{36, 40, 7, 39, 41, 15}
    x2 = []float64{15, 6, 42, 41, 7, 36, 49, 40, 39, 47, 43}
    x3 = []float64{
        0.14082834, 0.09748790, 1.73131507, 0.87636009, -1.95059594,
        0.73438555, -0.03035726, 1.46675970, -0.74621349, -0.72588772,
        0.63905160, 0.61501527, -0.98983780, -1.00447874, -0.62759469,
        0.66206163, 1.04312009, -0.10305385, 0.75775634, 0.32566578,
    }
)

func main() {
    fmt.Println(fivenum(x1))
    fmt.Println(fivenum(x2))
    fmt.Println(fivenum(x3))
}
Output:
[7 15 37.5 40 41]
[6 25.5 40 42.5 49]
[-1.95059594 -0.676741205 0.23324706 0.746070945 1.73131507]

Alternate:

This solution is aimed at handling larger data sets more efficiently. It replaces the O(n log n) sort with O(n) quickselect. It also does not attempt to reproduce the R result exactly, to average values to get a median of an even number of data values, or otherwise estimate quantiles. The quickselect here leaves the input partitioned around the selected value, which allows another small optimization: The first quickselect call partitions the full input around the median. The second call, to get the first quartile, thus only has to process the partition up to the median. The third call, to get the minimum, only has to process the partition up to the first quartile. The 3rd quartile and maximum are obtained similarly.

package main

import (
    "fmt"
    "math/rand"
)

func fivenum(a []float64) (n [5]float64) {
    last := len(a) - 1
    m := last / 2
    n[2] = qsel(a, m)
    q1 := len(a) / 4
    n[1] = qsel(a[:m], q1)
    n[0] = qsel(a[:q1], 0)
    a = a[m:]
    q3 := last - m - q1
    n[3] = qsel(a, q3)
    a = a[q3:]
    n[4] = qsel(a, len(a)-1)
    return
}

func qsel(a []float64, k int) float64 {
    for len(a) > 1 {
        px := rand.Intn(len(a))
        pv := a[px]
        last := len(a) - 1
        a[px], a[last] = a[last], pv
        px = 0
        for i, v := range a[:last] {
            if v < pv {
                a[px], a[i] = v, a[px]
                px++
            }
        }
        a[px], a[last] = pv, a[px]
        if px == k {
            return pv
        }
        if k < px {
            a = a[:px]
        } else {
            a = a[px+1:]
            k -= px + 1
        }
    }
    return a[0]
}

var (
    x1 = []float64{36, 40, 7, 39, 41, 15}
    x2 = []float64{15, 6, 42, 41, 7, 36, 49, 40, 39, 47, 43}
    x3 = []float64{
        0.14082834, 0.09748790, 1.73131507, 0.87636009, -1.95059594,
        0.73438555, -0.03035726, 1.46675970, -0.74621349, -0.72588772,
        0.63905160, 0.61501527, -0.98983780, -1.00447874, -0.62759469,
        0.66206163, 1.04312009, -0.10305385, 0.75775634, 0.32566578,
    }
)

func main() {
    fmt.Println(fivenum(x1))
    fmt.Println(fivenum(x2))
    fmt.Println(fivenum(x3))
}
Output:
[7 15 36 40 41]
[6 15 40 43 49]
[-1.95059594 -0.62759469 0.14082834 0.73438555 1.73131507]

Groovy

Translation of: Java
class Fivenum {
    static double median(double[] x, int start, int endInclusive) {
        int size = endInclusive - start + 1
        if (size <= 0) {
            throw new IllegalArgumentException("Array slice cannot be empty")
        }
        int m = start + (int) (size / 2)
        return (size % 2 == 1) ? x[m] : (x[m - 1] + x[m]) / 2.0
    }

    static double[] fivenum(double[] x) {
        for (Double d : x) {
            if (d.isNaN()) {
                throw new IllegalArgumentException("Unable to deal with arrays containing NaN")
            }
        }
        double[] result = new double[5]
        Arrays.sort(x)
        result[0] = x[0]
        result[2] = median(x, 0, x.length - 1)
        result[4] = x[x.length - 1]
        int m = (int) (x.length / 2)
        int lowerEnd = (x.length % 2 == 1) ? m : m - 1
        result[1] = median(x, 0, lowerEnd)
        result[3] = median(x, m, x.length - 1)
        return result
    }

    static void main(String[] args) {
        double[][] xl = [
            [15.0, 6.0, 42.0, 41.0, 7.0, 36.0, 49.0, 40.0, 39.0, 47.0, 43.0],
            [36.0, 40.0, 7.0, 39.0, 41.0, 15.0],
            [
                0.14082834, 0.09748790, 1.73131507, 0.87636009, -1.95059594, 0.73438555,
                -0.03035726, 1.46675970, -0.74621349, -0.72588772, 0.63905160, 0.61501527,
                -0.98983780, -1.00447874, -0.62759469, 0.66206163, 1.04312009, -0.10305385,
                0.75775634, 0.32566578
            ]
        ]
        for (double[] x : xl) {
            println("${fivenum(x)}")
        }
    }
}
Output:
[6.0, 25.5, 40.0, 42.5, 49.0]
[7.0, 15.0, 37.5, 40.0, 41.0]
[-1.95059594, -0.676741205, 0.23324706, 0.746070945, 1.73131507]

Haskell

Translation of: Python
import Data.List (sort)

fivenum :: [Double] -> [Double]
fivenum [] = []
fivenum xs
  | l >= 5 =
    fmap
      ( (/ 2)
          . ( (+) . (!!) s
                . floor
                <*> (!!) s . ceiling
            )
          . pred
      )
      [1, q, succ l / 2, succ l - q, l]
  | otherwise = s
  where
    l = realToFrac $ length xs
    q = realToFrac (floor $ (l + 3) / 2) / 2
    s = sort xs

main :: IO ()
main =
  print $
    fivenum
      [ 0.14082834,
        0.09748790,
        1.73131507,
        0.87636009,
        -1.95059594,
        0.73438555,
        -0.03035726,
        1.46675970,
        -0.74621349,
        -0.72588772,
        0.63905160,
        0.61501527,
        -0.98983780,
        -1.00447874,
        -0.62759469,
        0.66206163,
        1.04312009,
        -0.10305385,
        0.75775634,
        0.32566578
      ]
Output:
[-1.95059594,-0.676741205,0.23324706,0.746070945,1.73131507]

J

Solution

midpts=: (1 + #) <:@(] , -:@[ , -) -:@<.@-:@(3 + #) NB. mid points of y
quartiles=: -:@(+/)@((<. ,: >.)@midpts { /:~@])  NB. quartiles of y
fivenum=: <./ , quartiles , >./                  NB. fivenum summary of y

Example Usage

   test1=: 15 6 42 41 7 36 49 40 39 47 43
   test2=: 36 40 7 39 41 15
   test3=: , 0 ". ];._2 noun define
 0.14082834  0.09748790  1.73131507  0.87636009 -1.95059594
 0.73438555 -0.03035726  1.46675970 -0.74621349 -0.72588772
 0.63905160  0.61501527 -0.98983780 -1.00447874 -0.62759469
 0.66206163  1.04312009 -0.10305385  0.75775634  0.32566578
)
   fivenum &> test1;test2;test3
      6      25.5       40     42.5      49
      7        15     37.5       40      41
_1.9506 _0.676741 0.233247 0.746071 1.73132

Java

Translation of: Kotlin
import java.util.Arrays;

public class Fivenum {

    static double median(double[] x, int start, int endInclusive) {
        int size = endInclusive - start + 1;
        if (size <= 0) throw new IllegalArgumentException("Array slice cannot be empty");
        int m = start + size / 2;
        return (size % 2 == 1) ? x[m] : (x[m - 1] + x[m]) / 2.0;
    }

    static double[] fivenum(double[] x) {
        for (Double d : x) {
            if (d.isNaN())
                throw new IllegalArgumentException("Unable to deal with arrays containing NaN");
        }
        double[] result = new double[5];
        Arrays.sort(x);
        result[0] = x[0];
        result[2] = median(x, 0, x.length - 1);
        result[4] = x[x.length - 1];
        int m = x.length / 2;
        int lowerEnd = (x.length % 2 == 1) ? m : m - 1;
        result[1] = median(x, 0, lowerEnd);
        result[3] = median(x, m, x.length - 1);
        return result;
    }

    public static void main(String[] args) {
        double xl[][] = {
            {15.0, 6.0, 42.0, 41.0, 7.0, 36.0, 49.0, 40.0, 39.0, 47.0, 43.0},
            {36.0, 40.0, 7.0, 39.0, 41.0, 15.0},
            {
                 0.14082834,  0.09748790,  1.73131507,  0.87636009, -1.95059594,  0.73438555,
                -0.03035726,  1.46675970, -0.74621349, -0.72588772,  0.63905160,  0.61501527,
                -0.98983780, -1.00447874, -0.62759469,  0.66206163,  1.04312009, -0.10305385,
                 0.75775634,  0.32566578
            }
        };
        for (double[] x : xl) System.out.printf("%s\n\n", Arrays.toString(fivenum(x)));
    }
}
Output:
[6.0, 25.5, 40.0, 42.5, 49.0]

[7.0, 15.0, 37.5, 40.0, 41.0]

[-1.95059594, -0.676741205, 0.23324706, 0.746070945, 1.73131507]

JavaScript

function median(arr) {
  let mid = Math.floor(arr.length / 2);
  return (arr.length % 2 == 0) ? (arr[mid-1] + arr[mid]) / 2 : arr[mid];
}

Array.prototype.fiveNums = function() {
  this.sort(function(a, b) { return a - b} );
  let mid = Math.floor(this.length / 2),
      loQ = (this.length % 2 == 0) ? this.slice(0, mid) : this.slice(0, mid+1),
      hiQ = this.slice(mid);
  return [ this[0],
           median(loQ),
           median(this),
           median(hiQ),
           this[this.length-1] ];
}

// testing
let test = [15, 6, 42, 41, 7, 36, 49, 40, 39, 47, 43];
console.log( test.fiveNums() );

test = [0, 0, 1, 2, 63, 61, 27, 13];
console.log( test.fiveNums() );

test = [ 0.14082834,  0.09748790,  1.73131507,  0.87636009, -1.95059594,
         0.73438555, -0.03035726,  1.46675970, -0.74621349, -0.72588772,
         0.63905160,  0.61501527, -0.98983780, -1.00447874, -0.62759469,
         0.66206163,  1.04312009, -0.10305385,  0.75775634,  0.32566578];
console.log( test.fiveNums() );
Output:

> Array(5) [ 6, 25.5, 40, 42.5, 49 ] > Array(5) [ 0, 0.5, 7.5, 44, 63 ] > Array(5) [ -1.95059594, -0.676741205, 0.23324706, 0.746070945, 1.73131507 ]

jq

Translation of: Wren
def fivenum:
  def mid($i): 
    .[($i - 1)|floor] as $floor
    | .[($i - 1)|ceil] as $ceil
    | if $ceil == $floor then $ceil else ($floor+$ceil)/2 end;
  sort
  | length as $n
  | (($n + 3) / 2 | floor / 2) as $n4
  | [mid(1, $n4, (($n + 1)/2), $n + 1 - $n4, $n)] ;

def x1: [36, 40, 7, 39, 41, 15];
def x2: [15, 6, 42, 41, 7, 36, 49, 40, 39, 47, 43];
def x3: [
    0.14082834,  0.09748790,  1.73131507,  0.87636009, -1.95059594,
    0.73438555, -0.03035726,  1.46675970, -0.74621349, -0.72588772,
    0.63905160,  0.61501527, -0.98983780, -1.00447874, -0.62759469,
    0.66206163,  1.04312009, -0.10305385,  0.75775634,  0.32566578
];

[x1, x2, x3][] | fivenum
Output:

As for #Wren.

Julia

Works with: Julia version 0.6
function mediansorted(x::AbstractVector{T}, i::Integer, l::Integer)::T where T
    len = l - i + 1
    len > zero(len) || throw(ArgumentError("Array slice cannot be empty."))
    mid = i + len ÷ 2
    return isodd(len) ? x[mid] : (x[mid-1] + x[mid]) / 2
end

function fivenum(x::AbstractVector{T}) where T<:AbstractFloat
    r = Vector{T}(5)
    xs = sort(x)
    mid::Int = length(xs) ÷ 2
    lowerend::Int = isodd(length(xs)) ? mid : mid - 1
    r[1] = xs[1]
    r[2] = mediansorted(xs, 1, lowerend)
    r[3] = mediansorted(xs, 1, endof(xs))
    r[4] = mediansorted(xs, mid, endof(xs))
    r[end] = xs[end]
    return r
end

for v in ([15.0, 6.0, 42.0, 41.0, 7.0, 36.0, 49.0, 40.0, 39.0, 47.0, 43.0],
          [36.0, 40.0, 7.0, 39.0, 41.0, 15.0],
          [0.14082834,  0.09748790,  1.73131507,  0.87636009, -1.95059594,  0.73438555,
          -0.03035726,  1.46675970, -0.74621349, -0.72588772,  0.63905160,  0.61501527,
          -0.98983780, -1.00447874, -0.62759469,  0.66206163,  1.04312009, -0.10305385,
           0.75775634,  0.32566578])
    println("# ", v, "\n -> ", fivenum(v))
end
Output:
# [15.0, 6.0, 42.0, 41.0, 7.0, 36.0, 49.0, 40.0, 39.0, 47.0, 43.0]
 -> [6.0, 15.0, 40.0, 42.0, 49.0]
# [36.0, 40.0, 7.0, 39.0, 41.0, 15.0]
 -> [7.0, 11.0, 37.5, 39.5, 41.0]
# [0.140828, 0.0974879, 1.73132, 0.87636, -1.9506, 0.734386, -0.0303573, 1.46676, -0.746213, -0.725888, 0.639052, 0.615015, -0.989838, -1.00448, -0.627595,0.662062, 1.04312, -0.103054, 0.757756, 0.325666]
 -> [-1.9506, -0.725888, 0.233247, 0.734386, 1.73132]

Kotlin

The following uses Tukey's method for calculating the lower and upper quartiles (or 'hinges') which is what the R function, fivenum, appears to use.

As arrays containing NaNs and nulls cannot really be dealt with in a sensible fashion in Kotlin, they've been excluded altogether.

// version 1.2.21

fun median(x: DoubleArray, start: Int, endInclusive: Int): Double {
    val size = endInclusive - start + 1
    require (size > 0) { "Array slice cannot be empty" }
    val m = start + size / 2
    return if (size % 2 == 1) x[m] else (x[m - 1] + x[m]) / 2.0
}

fun fivenum(x: DoubleArray): DoubleArray {
    require(x.none { it.isNaN() }) { "Unable to deal with arrays containing NaN" }
    val result = DoubleArray(5)
    x.sort()
    result[0] = x[0]
    result[2] = median(x, 0, x.size - 1)
    result[4] = x[x.lastIndex]
    val m = x.size / 2
    var lowerEnd = if (x.size % 2 == 1) m else m - 1
    result[1] = median(x, 0, lowerEnd)
    result[3] = median(x, m, x.size - 1)
    return result
}

fun main(args: Array<String>) {
    var xl = listOf(
        doubleArrayOf(15.0, 6.0, 42.0, 41.0, 7.0, 36.0, 49.0, 40.0, 39.0, 47.0, 43.0),
        doubleArrayOf(36.0, 40.0, 7.0, 39.0, 41.0, 15.0),
        doubleArrayOf(
             0.14082834,  0.09748790,  1.73131507,  0.87636009, -1.95059594,  0.73438555,
            -0.03035726,  1.46675970, -0.74621349, -0.72588772,  0.63905160,  0.61501527,
            -0.98983780, -1.00447874, -0.62759469,  0.66206163,  1.04312009, -0.10305385,
             0.75775634,  0.32566578
        )
    )
    xl.forEach { println("${fivenum(it).asList()}\n") }
}
Output:
[6.0, 25.5, 40.0, 42.5, 49.0]

[7.0, 15.0, 37.5, 40.0, 41.0]

[-1.95059594, -0.676741205, 0.23324706, 0.746070945, 1.73131507]

Lua

function slice(tbl, low, high)
    local copy = {}

    for i=low or 1, high or #tbl do
        copy[#copy+1] = tbl[i]
    end

    return copy
end

-- assumes that tbl is sorted
function median(tbl)
    m = math.floor(#tbl / 2) + 1
    if #tbl % 2 == 1 then
        return tbl[m]
    end
    return (tbl[m-1] + tbl[m]) / 2
end

function fivenum(tbl)
    table.sort(tbl)

    r0 = tbl[1]
    r2 = median(tbl)
    r4 = tbl[#tbl]

    m = math.floor(#tbl / 2)
    if #tbl % 2 == 1 then
        low = m
    else
        low = m - 1
    end
    r1 = median(slice(tbl, nil, low+1))
    r3 = median(slice(tbl, low+2, nil))

    return r0, r1, r2, r3, r4
end

x1 = {
    {15.0, 6.0, 42.0, 41.0, 7.0, 36.0, 49.0, 40.0, 39.0, 47.0, 43.0},
    {36.0, 40.0, 7.0, 39.0, 41.0, 15.0},
    {
        0.14082834,  0.09748790,  1.73131507,  0.87636009, -1.95059594,  0.73438555,
       -0.03035726,  1.46675970, -0.74621349, -0.72588772,  0.63905160,  0.61501527,
       -0.98983780, -1.00447874, -0.62759469,  0.66206163,  1.04312009, -0.10305385,
        0.75775634,  0.32566578
    }
}

for i,x in ipairs(x1) do
    print(fivenum(x))
end
Output:
6       25.5    40      43      49
7       15      37.5    40      41
-1.95059594     -0.676741205    0.23324706      0.746070945     1.73131507

MATLAB / Octave

function r = fivenum(x)
	r = quantile(x,[0:4]/4);
end;


Output:

fivenum([15, 6, 42, 41, 7, 36, 49, 40, 39, 47, 43])
ans =
    6.0000   20.2500   40.0000   42.7500   49.0000

fivenum([36, 40, 7, 39, 41, 15])
ans =
    7.0000   15.0000   37.5000   40.0000   41.0000

fivenum([0.14082834, 0.0974879, 1.73131507, 0.87636009, -1.95059594, 0.73438555, -0.03035726, 1.4667597, -0.74621349, -0.72588772, 0.6390516, 0.61501527, -0.9898378, -1.00447874, -0.62759469, 0.66206163, 1.04312009, -0.10305385, 0.75775634, 0.32566578])
ans =
  -1.95060  -0.67674   0.23325   0.74607   1.73132

Mathematica / Wolfram Language

ClearAll[FiveNum]
FiveNum[x_List] := Quantile[x, Range[0, 1, 1/4]]
FiveNum[RandomVariate[NormalDistribution[], 10000]]
Output:
{-3.70325, -0.686977, -0.0087185, 0.652979, 3.67416}

Modula-2

MODULE Fivenum;
FROM FormatString IMPORT FormatString;
FROM LongStr IMPORT RealToStr;
FROM Terminal IMPORT WriteString,WriteLn,ReadChar;

PROCEDURE WriteLongReal(v : LONGREAL);
VAR buf : ARRAY[0..63] OF CHAR;
BEGIN
    RealToStr(v, buf);
    WriteString(buf)
END WriteLongReal;

PROCEDURE WriteArray(arr : ARRAY OF LONGREAL);
VAR i : CARDINAL;
BEGIN
    WriteString("[");
    FOR i:=0 TO HIGH(arr) DO
        WriteLongReal(arr[i]);
        WriteString(", ")
    END;
    WriteString("]")
END WriteArray;

(* Assumes that the input is sorted *)
PROCEDURE Median(x : ARRAY OF LONGREAL; beg,end : CARDINAL) : LONGREAL;
VAR m,cnt : CARDINAL;
BEGIN
    cnt := end - beg + 1;
    m := cnt / 2;
    IF cnt MOD 2 = 1 THEN
        RETURN x[beg + m]
    END;
    RETURN (x[beg + m - 1] + x[beg + m]) / 2.0
END Median;

TYPE Summary = ARRAY[0..4] OF LONGREAL;
PROCEDURE Fivenum(input : ARRAY OF LONGREAL) : Summary;
    PROCEDURE Sort();
    VAR
        i,j : CARDINAL;
        t : LONGREAL;
    BEGIN
        FOR i:=0 TO HIGH(input) DO
            FOR j:=0 TO HIGH(input) DO
                IF (i#j) AND (input[i] < input[j]) THEN
                    t := input[i];
                    input[i] := input[j];
                    input[j] := t
                END
            END
        END
    END Sort;
VAR
    result : Summary;
    size,m,low : CARDINAL;
BEGIN
    size := HIGH(input);
    Sort();

    result[0] := input[0];
    result[2] := Median(input,0,size);
    result[4] := input[size];

    m := size / 2;
    IF (size MOD 2 = 1) THEN
        low := m
    ELSE
        low := m - 1
    END;
    result[1] := Median(input, 0, m);
    result[3] := Median(input, m+1, size);

    RETURN result;
END Fivenum;

TYPE
    A6 = ARRAY[0..5] OF LONGREAL;
    A11 = ARRAY[0..10] OF LONGREAL;
    A20 = ARRAY[0..19] OF LONGREAL;
VAR
    a6 : A6;
    a11 : A11;
    a20 : A20;
BEGIN
    a11 := A11{15.0, 6.0, 42.0, 41.0, 7.0, 36.0, 49.0, 40.0, 39.0, 47.0, 43.0};
    WriteArray(Fivenum(a11));
    WriteLn;
    WriteLn;

    a6 := A6{36.0, 40.0, 7.0, 39.0, 41.0, 15.0};
    WriteArray(Fivenum(a6));
    WriteLn;
    WriteLn;

    a20 := A20{
        0.14082834,  0.09748790,  1.73131507,  0.87636009, -1.95059594,  0.73438555,
        -0.03035726,  1.46675970, -0.74621349, -0.72588772,  0.63905160,  0.61501527,
        -0.98983780, -1.00447874, -0.62759469,  0.66206163,  1.04312009, -0.10305385,
        0.75775634,  0.32566578
    };
    WriteArray(Fivenum(a20));
    WriteLn;

    ReadChar
END Fivenum.
Output:
[6.000000000000000, 25.499999999999900, 40.000000000000000, 42.499999999999900, 49.000000000000000, ]

[7.000000000000000, 15.000000000000000, 35.500000000000000, 40.000000000000000, 40.499999999999900, ]

[-1.950594000000000, -0.676741205000000, 0.233247060000000, 0.746070945000000, 1.731315070000000, ]

Nim

Translation of: Kotlin
import algorithm

type FiveNum = array[5, float]

template isOdd(n: SomeInteger): bool = (n and 1) != 0

func median(x: openArray[float]; startIndex, endIndex: Natural): float =
  let size = endIndex - startIndex + 1
  assert(size > 0, "array slice cannot be empty")
  let m = startIndex + size div 2
  result = if size.isOdd: x[m] else: (x[m-1] + x[m]) / 2

func fivenum(x: openArray[float]): FiveNum =
  let x = sorted(x)
  let m = x.len div 2
  let lowerEnd = if x.len.isOdd: m else: m - 1
  result[0] = x[0]
  result[1] = median(x, 0, lowerEnd)
  result[2] = median(x, 0, x.high)
  result[3] = median(x, m, x.high)
  result[4] = x[^1]

const Lists = [@[15.0, 6.0, 42.0, 41.0, 7.0, 36.0, 49.0, 40.0, 39.0, 47.0, 43.0],
               @[36.0, 40.0, 7.0, 39.0, 41.0, 15.0],
               @[0.14082834,  0.09748790,  1.73131507,  0.87636009, -1.95059594,
                 0.73438555, -0.03035726,  1.46675970, -0.74621349, -0.72588772,
                 0.63905160,  0.61501527, -0.98983780, -1.00447874, -0.62759469,
                 0.66206163,  1.04312009, -0.10305385,  0.75775634,  0.32566578]]

for list in Lists:
  echo ""
  echo list
  echo "  →  ", list.fivenum
Output:
@[15.0, 6.0, 42.0, 41.0, 7.0, 36.0, 49.0, 40.0, 39.0, 47.0, 43.0]
  →  [6.0, 25.5, 40.0, 42.5, 49.0]

@[36.0, 40.0, 7.0, 39.0, 41.0, 15.0]
  →  [7.0, 15.0, 37.5, 40.0, 41.0]

@[0.14082834, 0.0974879, 1.73131507, 0.87636009, -1.95059594, 0.7343855500000001, -0.03035726, 1.4667597, -0.74621349, -0.72588772, 0.6390516000000001, 0.61501527, -0.9898378, -1.00447874, -0.62759469, 0.66206163, 1.04312009, -0.10305385, 0.75775634, 0.32566578]
  →  [-1.95059594, -0.676741205, 0.23324706, 0.746070945, 1.73131507]

Perl

use POSIX qw(ceil floor);

sub fivenum {
   my(@array) = @_;
   my $n = scalar @array;
   die "No values were entered into fivenum!" if $n == 0;
   my @x = sort {$a <=> $b} @array;
   my $n4 = floor(($n+3)/2)/2;
   my @d = (1, $n4, ($n +1)/2, $n+1-$n4, $n);
   my @sum_array;
   for my $e (0..4) {
      my $floor = floor($d[$e]-1);
      my $ceil  =  ceil($d[$e]-1);
      push @sum_array, (0.5 * ($x[$floor] + $x[$ceil]));
   }
   return @sum_array;
}

my @x = (15, 6, 42, 41, 7, 36, 49, 40, 39, 47, 43);
my @tukey = fivenum(\@x);
say join (',', @tukey);
#----------
@x = (36, 40, 7, 39, 41, 15),
@tukey = fivenum(\@x);
say join (',', @tukey);
#----------
@x = (0.14082834,  0.09748790,  1.73131507,  0.87636009, -1.95059594,
     0.73438555, -0.03035726,  1.46675970, -0.74621349, -0.72588772,
     0.63905160,  0.61501527, -0.98983780, -1.00447874, -0.62759469,
     0.66206163,  1.04312009, -0.10305385,  0.75775634,  0.32566578);
@tukey = fivenum(\@x);
say join (',', @tukey);
Output:
6,25.5,40,42.5,49
7,15,37.5,40,41
-1.95059594,-0.676741205,0.23324706,0.746070945,1.73131507

Phix

with javascript_semantics
function median(sequence tbl, integer lo, hi)
    integer l = hi-lo+1
    integer m = lo+floor(l/2)
    if remainder(l,2)=1 then
        return tbl[m]
    end if
    return (tbl[m-1]+tbl[m])/2
end function
 
function fivenum(sequence tbl)
    tbl = sort(deep_copy(tbl))
    integer l = length(tbl),
            m = floor(l/2)+remainder(l,2)
 
    atom r1 = tbl[1],
         r2 = median(tbl,1,m),
         r3 = median(tbl,1,l),
         r4 = median(tbl,m+1,l),
         r5 = tbl[l]
 
    return {r1, r2, r3, r4, r5}
end function
 
constant x1 = {15, 6, 42, 41, 7, 36, 49, 40, 39, 47, 43},
         x2 = {36, 40, 7, 39, 41, 15},
         x3 = {0.14082834, 0.09748790, 1.73131507, 0.87636009, -1.95059594,
               0.73438555, -0.03035726, 1.46675970, -0.74621349, -0.72588772,
               0.63905160, 0.61501527, -0.98983780, -1.00447874, -0.62759469,
               0.66206163, 1.04312009, -0.10305385, 0.75775634, 0.32566578}
pp(fivenum(x1))
pp(fivenum(x2))
pp(fivenum(x3))
Output:
{6,25.5,40,43,49}
{7,15,37.5,40,41}
{-1.95059594,-0.676741205,0.23324706,0.746070945,1.73131507}

PicoLisp

(de median (Lst)
   (let N (length Lst)
      (if (bit? 1 N)
         (get Lst (/ (inc N) 2))
         (setq Lst (nth Lst (/ N 2)))
         (/ (+ (car Lst) (cadr Lst)) 2) ) ) )
(de fivenum (Lst)   # destructive
   (let
      (Len (length Lst)
         M (/ Len 2)
         S (sort Lst) )
      (list
         (format (car S) *Scl)
         (format
            (median (head (+ M (% Len 2)) S))
            *Scl )
         (format (median S) *Scl)
         (format (median (tail M S)) *Scl)
         (format (last S) *Scl) ) ) )
(scl 2)
(println (fivenum (36.0 40.0 7.0 39.0 41.0 15.0)))
(scl 8)
(println
   (fivenum
      (0.14082834 0.09748790 1.73131507 0.87636009 -1.95059594
         0.73438555 -0.03035726 1.46675970 -0.74621349 -0.72588772
         0.63905160 0.61501527 -0.98983780 -1.00447874 -0.62759469
         0.66206163 1.04312009 -0.10305385 0.75775634 0.32566578 ) ) )
Output:
("7.00" "15.00" "37.50" "40.00" "41.00")
("-1.95059594" "-0.67674120" "0.23324706" "0.74607094" "1.73131507")

Python

Python: Standard commands

Translation of: Perl

Work with: Python 2

Work with: Python 3

from __future__ import division
import math
import sys

def fivenum(array):
    n = len(array)
    if n == 0:
        print("you entered an empty array.")
        sys.exit()
    x = sorted(array)
    
    n4 = math.floor((n+3.0)/2.0)/2.0
    d = [1, n4, (n+1)/2, n+1-n4, n]
    sum_array = []
    
    for e in range(5):
        floor = int(math.floor(d[e] - 1))
        ceil = int(math.ceil(d[e] - 1))
        sum_array.append(0.5 * (x[floor] + x[ceil]))
    
    return sum_array

x = [0.14082834, 0.09748790, 1.73131507, 0.87636009, -1.95059594, 0.73438555, -0.03035726, 1.46675970,
-0.74621349, -0.72588772, 0.63905160, 0.61501527, -0.98983780, -1.00447874, -0.62759469, 0.66206163,
1.04312009, -0.10305385, 0.75775634, 0.32566578]

y = fivenum(x)
print(y)
Output:
[-1.95059594, -0.676741205, 0.23324706, 0.746070945, 1.73131507]

Python: Pandas library

There are many ways to compute this kind of summary statistics (see wp:Percentile#Definitions). The Python Pandas library supports a range.

Pandas is a well known Python library. Its Dataframe.describe method produces summary stats from data.

(Though these 25% and 75% values do not correspond to the Fivenum Tukey quartile values specified in this task)

import pandas as pd
pd.DataFrame([1, 2, 3, 4, 5, 6]).describe()
Output:
              0
count  6.000000
mean   3.500000
std    1.870829
min    1.000000
25%    2.250000
50%    3.500000
75%    4.750000
max    6.000000

To get the fivenum values asked for, the pandas.DataFrame.quantile function can be used:

import pandas as pd
pd.DataFrame([1, 2, 3, 4, 5, 6]).quantile([.0, .25, .50, .75, 1.00], interpolation='nearest')
Output:
      0
0.00  1
0.25  2
0.50  3
0.75  5
1.00  6

The interpolation value supports more of the differing ways of calculation in use.

Python: Functional – without imports

Works with: Python 3

# fiveNums :: [Float] -> (Float, Float, Float, Float, Float)
def fiveNums(xs):
    def median(xs):
        lng = len(xs)
        m = lng // 2
        return xs[m] if (
            0 != lng % 2
        ) else (xs[m - 1] + xs[m]) / 2
 
    ys = sorted(xs)
    lng = len(ys)
    m = lng // 2
    return (
        ys[0], 
        median(ys[0:(m + (lng % 2))]),
        median(ys), 
        median(ys[m:]), 
        ys[-1]
    ) if 0 < lng else None
 
 
# TEST --------------------------------------------------------------------
for xs in [[15, 6, 42, 41, 7, 36, 49, 40, 39, 47, 43],
           [36, 40, 7, 39, 41, 15],
           [
               0.14082834, 0.09748790, 1.73131507, 0.87636009, -1.95059594,
               0.73438555, -0.03035726, 1.46675970, -0.74621349, -0.72588772,
               0.63905160, 0.61501527, -0.98983780, -1.00447874, -0.62759469,
               0.66206163, 1.04312009, -0.10305385, 0.75775634, 0.32566578
           ]]:
    print(
        fiveNums(xs)
    )
Output:
(6, 25.5, 40, 42.5, 49)
(7, 15, 37.5, 40, 41)
(-1.95059594, -0.676741205, 0.23324706, 0.746070945, 1.73131507)

R

The fivenum function is built-in, see R manual.

x <- c(0.14082834, 0.09748790, 1.73131507, 0.87636009, -1.95059594,  0.73438555,-0.03035726, 1.46675970, -0.74621349, -0.72588772, 0.63905160, 0.61501527, -0.98983780, -1.00447874, -0.62759469, 0.66206163, 1.04312009, -0.10305385, 0.75775634,  0.32566578)

fivenum(x)

Output

[1] -1.9505959 -0.6767412  0.2332471  0.7460709  1.7313151

Racket

Racket's =quantile= functions use a different method to Tukey; so a new implementation was made.

#lang racket/base
(require math/private/statistics/quickselect)

;; racket's quantile uses "Method 1" of https://en.wikipedia.org/wiki/Quartile
;; Tukey (fivenum) uses "Method 2", so we will need a specialist median
(define (fivenum! data-v)
  (define (tukey-median start end)
    (define-values (n/2 parity) (quotient/remainder (- end start) 2))
    (define mid (+ start n/2))
    (if (zero? parity)
        (/ (+ (data-kth-value! (+ mid (sub1 parity))) (data-kth-value! mid)) 2)
        (data-kth-value! mid)))

  (define n-data (let ((l (vector-length data-v)))
                   (if (zero? l)
                       (raise-argument-error 'data-v "nonempty (Vectorof Real)" data-v)
                       l)))
  
  (define (data-kth-value! n) (kth-value! data-v n <))

  (define subset-size (let-values (((n/2 parity) (quotient/remainder n-data 2))) (+ n/2 parity)))
  
  (vector (data-kth-value! 0)
          (tukey-median 0 subset-size)
          (tukey-median 0 n-data)
          (tukey-median (- n-data subset-size) n-data)
          (data-kth-value! (sub1 n-data))))

(define (fivenum data-seq)
  (fivenum! (if (and (vector? data-seq) (not (immutable? data-seq)))
                data-seq
                (for/vector ((datum data-seq)) datum))))

(module+ test
  (require rackunit
           racket/vector)
  (check-equal? #(14 14 14 14 14) (fivenum #(14)) "Minimal case")
  (check-equal? #(8 11 14 17 20) (fivenum #(8 14 20)) "3-value case")
  (check-equal? #(8 11 15 18 20) (fivenum #(8 14 16 20)) "4-value case")

  (define x1-seq #(36 40 7 39 41 15))
  (define x1-v (vector-copy x1-seq))
  (check-equal? x1-seq x1-v "before fivenum! sequence and vector were not `equal?`")
  (check-equal? #(7 15 #e37.5 40 41) (fivenum! x1-v) "Test against Go results x1")
  (check-not-equal? x1-seq x1-v "fivenum! did not mutate mutable input vectors")
  
  (check-equal? #(6 #e25.5 40 #e42.5 49) (fivenum #(15 6 42 41 7 36 49 40 39 47 43)) "Test against Go results x2")
  
  (check-equal? #(-1.95059594 -0.676741205 0.23324706 0.746070945 1.73131507)
                (fivenum (vector 0.14082834  0.09748790  1.73131507  0.87636009 -1.95059594  0.73438555
                                 -0.03035726  1.46675970 -0.74621349 -0.72588772  0.63905160  0.61501527
                                 -0.98983780 -1.00447874 -0.62759469  0.66206163  1.04312009 -0.10305385
                                 0.75775634  0.32566578))
                "Test against Go results x3"))

This program passes its tests silently.

Raku

(formerly Perl 6)

Translation of: Perl
sub fourths ( Int $end ) {
    my $end_22 = $end div 2 / 2;

    return 0, $end_22, $end/2, $end - $end_22, $end;
}
sub fivenum ( @nums ) {
    my @x = @nums.sort(+*)
        or die 'Input must have at least one element';

    my @d = fourths(@x.end);

    return ( @x[@d».floor] Z+ @x[@d».ceiling] ) »/» 2;
}

say .&fivenum for [15, 6, 42, 41, 7, 36, 49, 40, 39, 47, 43],
                  [36, 40, 7, 39, 41, 15], [
    0.14082834,  0.09748790,  1.73131507,  0.87636009, -1.95059594,
    0.73438555, -0.03035726,  1.46675970, -0.74621349, -0.72588772,
    0.63905160,  0.61501527, -0.98983780, -1.00447874, -0.62759469,
    0.66206163,  1.04312009, -0.10305385,  0.75775634,  0.32566578,
];
Output:
(6 25.5 40 42.5 49)
(7 15 37.5 40 41)
(-1.95059594 -0.676741205 0.23324706 0.746070945 1.73131507)

Relation

Min, median and max are built in, quarter1 and quarter3 calculated.

program fivenum(X)
rename X^ x
order x 1
dup
project x min, x median, x max, x count
set q1 = x_count / 4
set q1min = floor(q1)
set q1weight = q1 - q1min
set q3 = x_count * 3 / 4
set q3min = floor(q3)
set q3weight = q3 - q3min
swap
dup
select rownumber = q1min + 1 or rownumber = q1min + 2
extend w = q1weight * (rownumber - 1) - (rownumber-1-1) * (1-q1weight)
extend xw = x * w
project xw sum
rename xw_sum x_quarter1
swap
select rownumber = q3min + 1 or rownumber = q3min + 2
extend w = q3weight * (rownumber - 1) - (rownumber-1-1) * (1-q3weight)
extend xw = x * w
project xw sum
rename xw_sum x_quarter3
join cross
join cross
project x_min, x_quarter1, x_median, x_quarter3, x_max
print
end program

relation a
insert 3
insert 4
insert 18
insert 12
insert 17
insert 5
insert 6
insert 11
insert 8
run fivenum("a")
Output:
x_min x_quarter1 x_median x_quarter3 x_max
3 5.25 8 15.75 18

REXX

Programming note:   this REXX program uses a unity─based array.

/*REXX program computes the five─number summary  (LO─value, p25, medium, p75, HI─value).*/
parse arg x
if x=''  then x= 15 6 42 41 7 36 49 40 39 47 43  /*Not specified?  Then use the defaults*/
say 'input numbers: '     space(x)               /*display the original list of numbers.*/
call 5num                                        /*invoke the  five─number  function.   */
say ' five─numbers: '     result                 /*display "     "     "    results.    */
exit                                             /*stick a fork in it,  we're all done. */
/*──────────────────────────────────────────────────────────────────────────────────────*/
bSort: procedure expose @.;  parse arg n;  m=n-1 /*N:  the number of  @  array elements.*/
         do m=m  for m  by -1  until ok;   ok= 1 /*keep sorting the  @  array 'til done.*/
           do j=1  for m;      k= j + 1;         /*set  K  to the next item in  @ array.*/
           if @.j<=@.k  then iterate             /*Is  @.J  in numerical order?   Good. */
           parse value @.j @.k 0 with @.k @.j ok /*swap two elements and  flag as ¬done.*/
           end   /*j*/
         end     /*m*/;          return
/*──────────────────────────────────────────────────────────────────────────────────────*/
med:   arg s,e;  $=e-s+1;  m=s+$%2;  if $//2  then return @.m;  _=m-1;  return (@._+@.m)/2
/*──────────────────────────────────────────────────────────────────────────────────────*/
5num:  #= words(x);                  if #==0  then return  '***error***  array is empty.'
       parse var x . 1 LO . 1 HI .               /*assume values for LO and HI (for now)*/
       q2= # % 2;                                er= '***error***  element'
                     do j=1  for #;     @.j= word(x, j)
                     if \datatype(@.j, 'N')  then return  er   j   "isn't numeric: "   @.j
                     LO= min(LO, @.j);  HI= max(HI, @.j)
                     end   /*j*/                 /* [↑] traipse thru array, find min,max*/
       call bSort #                              /*use a bubble sort (easiest to code). */
       if #//2  then p25= q2                     /*calculate the second quartile number.*/
                else p25= q2 - 1                 /*    "      "     "       "       "   */
       return LO  med(1, p25)   med(1, #)   med(q2, #)   HI  /*return list of 5 numbers.*/
output   when using the default input of:     15 6 42 41 7 36 49 40 39 47 43
input numbers:  15 6 42 41 7 36 49 40 39 47 43
 five─numbers:  6 15 40 42 49
output   when using the (internal) default inputs of:     36 40 7 39 41 15
input numbers:  36 40 7 39 41 15
 five─numbers:  7 11 37.5 39.5 41

Ring

rem1 = 0
rem2 = 0
rem3 = 0
rem4 = 0
rem5 = 0
fn1 = [15, 6, 42, 41, 7, 36, 49, 40, 39, 47, 43]
fn2 = [36, 40, 7, 39, 41, 15]
fn3 = [0.14082834, 0.09748790, 1.73131507, 0.87636009, -1.95059594,
      0.73438555, -0.03035726, 1.46675970, -0.74621349, -0.72588772,
      0.63905160, 0.61501527, -0.98983780, -1.00447874, -0.62759469,
      0.66206163, 1.04312009, -0.10305385, 0.75775634, 0.32566578]
decimals(1)
fivenum(fn1) showarray([rem1,rem2,rem3,rem4,rem5])
fivenum(fn2) showarray([rem1,rem2,rem3,rem4,rem5])
decimals(8)
fivenum(fn3) showarray([rem1,rem2,rem3,rem4,rem5])

func median(table,low,high)
     l = high-low+1
     m = low + floor(l/2)
     if l%2 = 1
         return table[m]
     ok
     return (table[m-1]+table[m])/2
 
func fivenum(table)
     table = sort(table)
     low   = len(table)
     m     = floor(low/2)+low%2
     rem1  = table[1]
     rem2  = median(table,1,m)
     rem3  = median(table,1,low)
     rem4  = median(table,m+1,low)
     rem5  = table[low] 
     return [rem1, rem2, rem3, rem4, rem5]

func showarray vect
     svect = ""
     for n in vect
         svect += " " + n + ","
     next
     ? "[" + left(svect, len(svect) - 1) + "]"
Output:
[6,25.5,40,43,49]
[7,15,37.5,40,41]
[-1.95059594,-0.67674121,0.23324706,0.74607095,1.73131507]

RPL

Works with: Halcyon Calc version 4.2.7
IF DUP SIZE 2 ≥ THEN
     LIST→ → len 
     ≪ len 1 FOR n 
           1 n 1 - START 
              IF DUP2 > THEN SWAP END 
              n ROLLD 
           NEXT n ROLLD  
       -1 STEP len →LIST
     ≫ END
≫ ‘SORTL’ STO

≪ → data n 
   ≪ data SIZE n * 4 n - + 4 / 
      data OVER FLOOR GET n * 
      data ROT CEIL GET 4 n - * + 4 / 
≫ ≫ ‘QTL’ STO

≪ SORTL { } 
   OVER 1 GET + OVER 1 QTL + OVER 2 QTL + OVER 3 QTL + OVER DUP SIZE GET + 
≫ ‘SUMR5’ STO

{ 6 7 15 36 39 40 41 42 43 47 49 } SUMR5
Output:
1: { 6 30.75 40 42.25 49 }

Ruby

Translation of: Perl
def fivenum(array)
  sorted_arr = array.sort
  n = array.size
  n4 = (((n + 3).to_f / 2.to_f) / 2.to_f).floor
  d = Array.[](1, n4, ((n.to_f + 1) / 2).to_i, n + 1 - n4, n)
  sum_array = []
  (0..4).each do |e| # each loops have local scope, for loops don't
    index_floor = (d[e] - 1).floor
    index_ceil  = (d[e] - 1).ceil
    sum_array.push(0.5 * (sorted_arr[index_floor] + sorted_arr[index_ceil]))
  end
  sum_array
end

test_array = [15, 6, 42, 41, 7, 36, 49, 40, 39, 47, 43]
tukey_array = fivenum(test_array)
p tukey_array
test_array = [36, 40, 7, 39, 41, 15]
tukey_array = fivenum(test_array)
p tukey_array
test_array = [0.14082834, 0.09748790, 1.73131507, 0.87636009, -1.95059594,
              0.73438555, -0.03035726, 1.46675970, -0.74621349, -0.72588772,
              0.63905160,  0.61501527, -0.98983780, -1.00447874, -0.62759469,
              0.66206163,  1.04312009, -0.10305385, 0.75775634,  0.32566578]
tukey_array = fivenum(test_array)
p tukey_array
Output:
[6.0, 15.0, 40.0, 43.0, 49.0]
[7.0, 15.0, 36.0, 40.0, 41.0]
[-1.95059594, -0.72588772, 0.14082834, 0.75775634, 1.73131507]

Rust

#[derive(Debug)]
struct FiveNum {
    minimum: f64,
    lower_quartile: f64,
    median: f64,
    upper_quartile: f64,
    maximum: f64,
}

fn median(samples: &[f64]) -> f64 {
    // input is already sorted
    let n = samples.len();
    let m = n / 2;
    if n % 2 == 0 {
        (samples[m] + samples[m - 1]) / 2.0
    } else {
        samples[m]
    }
}

fn fivenum(samples: &[f64]) -> FiveNum {
    let mut xs = samples.to_vec();
    xs.sort_by(|x, y| x.partial_cmp(y).unwrap());

    let m = xs.len() / 2;

    FiveNum {
        minimum: xs[0],
        lower_quartile: median(&xs[0..(m + (xs.len() % 2))]),
        median: median(&xs),
        upper_quartile: median(&xs[m..]),
        maximum: xs[xs.len() - 1],
    }
}
fn main() {
    let inputs = vec![
        vec![15., 6., 42., 41., 7., 36., 49., 40., 39., 47., 43.],
        vec![36., 40., 7., 39., 41., 15.],
        vec![
            0.14082834,
            0.09748790,
            1.73131507,
            0.87636009,
            -1.95059594,
            0.73438555,
            -0.03035726,
            1.46675970,
            -0.74621349,
            -0.72588772,
            0.63905160,
            0.61501527,
            -0.98983780,
            -1.00447874,
            -0.62759469,
            0.66206163,
            1.04312009,
            -0.10305385,
            0.75775634,
            0.32566578,
        ],
    ];

    for input in inputs {
        let result = fivenum(&input);
        println!("Fivenum",);
        println!("  Minumum: {}", result.minimum);
        println!("  Lower quartile: {}", result.lower_quartile);
        println!("  Median: {}", result.median);
        println!("  Upper quartile: {}", result.upper_quartile);
        println!("  Maximum: {}", result.maximum);
    }
}
Output:
Fivenum
  Minumum: 6
  Lower quartile: 25.5
  Median: 40
  Upper quartile: 42.5
  Maximum: 49
Fivenum
  Minumum: 7
  Lower quartile: 15
  Median: 37.5
  Upper quartile: 40
  Maximum: 41
Fivenum
  Minumum: -1.95059594
  Lower quartile: -0.676741205
  Median: 0.23324706
  Upper quartile: 0.746070945
  Maximum: 1.73131507

SAS

/* build a dataset */
data test;
do i=1 to 10000;
	x=rannor(12345);
	output;
end;
keep x;
run;

/* compute the five numbers */
proc means data=test min p25 median p75 max;
var x;
run;

Output

Analysis Variable : x
Minimum 25th Pctl Median 75th Pctl Maximum
-4.0692299 -0.6533022 0.0066299 0.6768043 4.1328026

Scala

Array based solution

import java.util

object Fivenum extends App {

  val xl = Array(
    Array(15.0, 6.0, 42.0, 41.0, 7.0, 36.0, 49.0, 40.0, 39.0, 47.0, 43.0),
    Array(36.0, 40.0, 7.0, 39.0, 41.0, 15.0),
    Array(0.14082834, 0.09748790, 1.73131507, 0.87636009, -1.95059594, 0.73438555,
      -0.03035726, 1.46675970, -0.74621349, -0.72588772, 0.63905160, 0.61501527, -0.98983780,
      -1.00447874, -0.62759469, 0.66206163, 1.04312009, -0.10305385, 0.75775634, 0.32566578)
  )

  for (x <- xl) println(f"${util.Arrays.toString(fivenum(x))}%s\n\n")

  def fivenum(x: Array[Double]): Array[Double] = {
    require(x.forall(!_.isNaN), "Unable to deal with arrays containing NaN")

    def median(x: Array[Double], start: Int, endInclusive: Int): Double = {
      val size = endInclusive - start + 1
      require(size > 0, "Array slice cannot be empty")
      val m = start + size / 2
      if (size % 2 == 1) x(m) else (x(m - 1) + x(m)) / 2.0
    }

    val result = new Array[Double](5)
    util.Arrays.sort(x)
    result(0) = x(0)
    result(2) = median(x, 0, x.length - 1)
    result(4) = x(x.length - 1)
    val m = x.length / 2
    val lowerEnd = if (x.length % 2 == 1) m else m - 1
    result(1) = median(x, 0, lowerEnd)
    result(3) = median(x, m, x.length - 1)
    result
  }

}
Output:
See it running in your browser by ScalaFiddle (JavaScript, non JVM) or by Scastie (JVM).

Sidef

Translation of: Raku
func fourths(e) {
    var t = ((e>>1) / 2)
    [0, t, e/2, e - t, e]
}

func fivenum(nums) {
    var x = nums.sort
    var d = fourths(x.end)

    ([x[d.map{.floor}]] ~Z+ [x[d.map{.ceil}]]) »/» 2
}

var nums = [
    [15, 6, 42, 41, 7, 36, 49, 40, 39, 47, 43],
    [36, 40, 7, 39, 41, 15], [
    0.14082834,  0.09748790,  1.73131507,  0.87636009, -1.95059594,
    0.73438555, -0.03035726,  1.46675970, -0.74621349, -0.72588772,
    0.63905160,  0.61501527, -0.98983780, -1.00447874, -0.62759469,
    0.66206163,  1.04312009, -0.10305385,  0.75775634,  0.32566578,
]]

nums.each { say fivenum(_).join(', ') }
Output:
6, 25.5, 40, 42.5, 49
7, 15, 37.5, 40, 41
-1.95059594, -0.676741205, 0.23324706, 0.746070945, 1.73131507

Stata

First build a dataset:

clear
set seed 17760704
qui set obs 10000
gen x=rnormal()

The summarize command produces all the required statistics, and more:

qui sum x, detail
di r(min),r(p25),r(p50),r(p75),r(max)

Output

-3.6345866 -.66536 .0026834 .68398139 3.7997103

It's also possible to use the tabstat command

tabstat x, s(mi q ma)

Output

    variable |       min       p25       p50       p75       max
-------------+--------------------------------------------------
           x | -3.634587   -.66536  .0026834  .6839814   3.79971
----------------------------------------------------------------

Another example:

clear
mat a=0.14082834\0.09748790\1.73131507\0.87636009\-1.95059594\ ///
	0.73438555\-0.03035726\1.46675970\-0.74621349\-0.72588772\ ///
	0.63905160\0.61501527\-0.98983780\-1.00447874\-0.62759469\ ///
	0.66206163\1.04312009\-0.10305385\0.75775634\0.32566578
svmat a
tabstat a1, s(mi q ma)

Output

    variable |       min       p25       p50       p75       max
-------------+--------------------------------------------------
          a1 | -1.950596 -.6767412  .2332471   .746071  1.731315
----------------------------------------------------------------

Wren

Translation of: Go
Library: Wren-sort
import "./sort" for Sort

var fivenum = Fn.new { |a|
    Sort.quick(a)
    var n5 = List.filled(5, 0)
    var n = a.count
    var n4 = ((n + 3)/2).floor / 2
    var d = [1, n4, (n + 1)/2, n + 1 - n4, n]
    var e = 0
    for (de in d) {
        var floor = (de - 1).floor
        var ceil  = (de - 1).ceil
        n5[e] = 0.5 * (a[floor] + a[ceil])
        e = e + 1
    }
    return n5
}

var x1 = [36, 40, 7, 39, 41, 15]
var x2 = [15, 6, 42, 41, 7, 36, 49, 40, 39, 47, 43]
var x3 = [
    0.14082834,  0.09748790,  1.73131507,  0.87636009, -1.95059594,
    0.73438555, -0.03035726,  1.46675970, -0.74621349, -0.72588772,
    0.63905160,  0.61501527, -0.98983780, -1.00447874, -0.62759469,
    0.66206163,  1.04312009, -0.10305385,  0.75775634,  0.32566578
]
for (x in [x1, x2, x3]) System.print(fivenum.call(x))
Output:
[7, 15, 37.5, 40, 41]
[6, 25.5, 40, 42.5, 49]
[-1.95059594, -0.676741205, 0.23324706, 0.746070945, 1.73131507]

zkl

Uses GNU GSL library.

var [const] GSL=Import("zklGSL");	// libGSL (GNU Scientific Library)
fcn fiveNum(v){ // V is a GSL Vector, --> min, 1st qu, median, 3rd qu, max
   v.sort();
   return(v.min(),v.quantile(0.25),v.median(),v.quantile(0.75),v.max())
}
fiveNum(GSL.VectorFromData(
   15.0, 6.0, 42.0, 41.0, 7.0, 36.0, 49.0, 40.0, 39.0, 47.0, 43.0)).println();
println(fiveNum(GSL.VectorFromData(36.0, 40.0, 7.0, 39.0, 41.0, 15.0)));

v:=GSL.VectorFromData(
   0.14082834,  0.09748790,  1.73131507,  0.87636009, -1.95059594,  0.73438555,
  -0.03035726,  1.46675970, -0.74621349, -0.72588772,  0.63905160,  0.61501527,
  -0.98983780, -1.00447874, -0.62759469,  0.66206163,  1.04312009, -0.10305385,
   0.75775634,  0.32566578);
println(fiveNum(v));
Output:
L(6,25.5,40,42.5,49)
L(7,20.25,37.5,39.75,41)
L(-1.9506,-0.652168,0.233247,0.740228,1.73132)