Hello again! I'm learning Factor little by little. Currently I'm trying to contribute a solution to Rosetta Code for the following pair of problems:
http://rosettacode.org/wiki/Seven-sided_dice_from_five-sided_dice http://rosettacode.org/wiki/Simple_Random_Distribution_Checker The code that I've got so far can be seen below. Please, comment and criticize: USING: kernel random math math.functions math.vectors sequences locals prettyprint ; IN: dice7 ! Output a random number 1..5. : dice5 ( -- x ) random-unit 5 * floor 1 + >integer ; ! Output a random number 1..7 using dice5 as randomness source. : dice7 ( -- x ) 0 [ dup 21 < ] [ drop dice5 5 * dice5 + 6 - ] do until 7 rem 1 + >integer ; ! Roll dice using the passed word the given number of times and produce an ! array with roll results. ! Sample call: \ dice7 1000 roll : roll ( word: ( -- x ) times -- array ) iota [ drop dup execute( -- x ) ] map nip ; ! Input array contains outcomes of a number of die throws. Each die result is ! an integer in the range 1..X. Calculate and return the number of each ! of the results in the array so that in the first position of the result ! there is the number of ones in the input array, in the second position ! of the result there is the number of twos in the input array, etc. : count-diceX-outcomes ( array X -- array ) iota [ 1 + dupd [ = ] curry count ] map swap length over sum assert= ; ! Verify distribution uniformity/Naive. Delta is the acceptable deviation ! from the ideal number of items in each bucket, expressed as a fraction of ! the total count. Sides is the number of die sides. Rnd-func is a word that ! produces a random number on stack in the range [1..sides], times is the ! number of times to call it. ! Sample call: 0.02 7 \ dice7 100000 verify :: verify ( delta sides rnd-func: ( -- random ) times -- ) rnd-func times roll sides count-diceX-outcomes dup . times sides / :> ideal-count ideal-count v-n vabs times v/n delta [ < ] curry map vall? [ "Random enough" . ] [ "Not random enough" . ] if ; ! Call verify with 1, 10, 100, ... 1000000 rolls of 7-sided die. : verify-all ( -- ) { 1 10 100 1000 10000 100000 1000000 } [| times | 0.02 7 \ dice7 times verify ] each ; ---=====--- Александр ------------------------------------------------------------------------------ BPM Camp - Free Virtual Workshop May 6th at 10am PDT/1PM EDT Develop your own process in accordance with the BPMN 2 standard Learn Process modeling best practices with Bonita BPM through live exercises http://www.bonitasoft.com/be-part-of-it/events/bpm-camp-virtual- event?utm_ source=Sourceforge_BPM_Camp_5_6_15&utm_medium=email&utm_campaign=VA_SF _______________________________________________ Factor-talk mailing list Factor-talk@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/factor-talk
