Fibonacci word: Difference between revisions
Content added Content deleted
(added Factor) |
(→{{header|Factor}}: drastically reduced memory usage and run time) |
||
| Line 1,186: | Line 1,186: | ||
=={{header|Factor}}== |
=={{header|Factor}}== |
||
It is not necessary to calculate each fibonacci word, since every fibonacci word less than 37 is contained in the 37th fibonacci word. In order to obtain the nth fibonacci word ( <= 37 ), we start with the 37th fibonacci word and take the subsequence from index 0 to the nth fibonacci number, as in the standard fibonacci sequence. |
|||
<lang factor>USING: assocs combinators formatting kernel math math.functions |
<lang factor>USING: assocs combinators formatting kernel math math.functions |
||
math.ranges math.statistics pair-rocket sequences ; |
math.ranges math.statistics namespaces pair-rocket sequences ; |
||
IN: rosetta-code.fibonacci-word |
IN: rosetta-code.fibonacci-word |
||
SYMBOL: 37th-fib-word |
|||
: fib ( n -- m ) |
|||
| ⚫ | |||
1 => [ 1 ] |
|||
2 => [ 1 ] |
|||
[ [ 1 - fib ] [ 2 - fib ] bi + ] |
|||
} case ; |
|||
: fib-word ( n -- seq ) |
: fib-word ( n -- seq ) |
||
{ |
{ |
||
1 => [ |
1 => [ "1" ] |
||
2 => [ |
2 => [ "0" ] |
||
[ [ 1 - fib-word ] [ 2 - fib-word ] bi append ] |
[ [ 1 - fib-word ] [ 2 - fib-word ] bi append ] |
||
} case ; |
} case ; |
||
: nth-fib-word ( n -- seq ) |
|||
dup 1 = |
|||
[ drop "1" ] [ 37th-fib-word get swap fib head ] if ; |
|||
: entropy ( seq -- entropy ) |
: entropy ( seq -- entropy ) |
||
| Line 1,202: | Line 1,216: | ||
[ dup log 2 log / * ] map-sum |
[ dup log 2 log / * ] map-sum |
||
dup 0. = [ neg ] unless ; |
dup 0. = [ neg ] unless ; |
||
| ⚫ | |||
37 fib-word 37th-fib-word set |
|||
"N" "Length" "Entropy" "%2s %8s %10s\n" printf |
"N" "Length" "Entropy" "%2s %8s %10s\n" printf |
||
37 [1,b] [ |
37 [1,b] [ |
||
dup nth-fib-word [ length ] [ entropy ] bi |
|||
"%2d %8d %.8f\n" printf |
|||
] each</lang> |
] each</lang> |
||
{{out}} |
{{out}} |
||