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A quick bit of Scheme/Racket to produce a list of randomized treatments across a group of subjects.
Usage:
(randomize-treatments #:list treatments #:forSubjectCount number-of-subjects)
given a list of treatments and an integer number of subjects, call '''randomize-treatments''':
> (define treatments '(drug1 drug2 drug3 drug4))
> (define number-of-subjects 6)
> (randomize-treatments #:list treatments #:forSubjectCount number-of-subjects)
6 drug2 drug1 drug3 drug4
5 drug3 drug4 drug2 drug1
4 drug3 drug2 drug1 drug4
3 drug1 drug4 drug3 drug2
2 drug2 drug3 drug4 drug1
1 drug4 drug2 drug3 drug1
done
>
Here is the racket file, randomize-treatments.rkt. The source listing is below.
#lang racket
; randomize-treatments
; given a list of treatments and a number of subjects,
; prints out a list of treatments for each subject
; see usage example at bottom
(define shuffle ; Returns a randomly re-ordered copy of list.
(lambda (list)
(if (< (length list) 2)
list
(let ((item (list-ref list (random (length list)))))
(cons item (shuffle (remove item list)))))))
(define display-list-with-tabs; prints a list with tabs between members
(lambda (list)
(if (> (length list) 0)
(begin
(display (car list))
(if (> (length (cdr list)) 0)
(display "\t")
#f)
(display-list-with-tabs (cdr list)))
(displayln "")
)))
(define randomize-treatments
; given a list of treatments and a number of subjects,
; prints out a list of treatments for each subject
(lambda (#:list rx-list #:forSubjectCount n )
(if (> n 0)
(begin
(display n)(display "\t")
(display-list-with-tabs (shuffle rx-list))
(randomize-treatments #:list rx-list #:forSubjectCount (sub1 n)))
(displayln 'done)
)))
; usage
;(define treatments '(drug1 drug2 drug3 drug4))
;(define number-of-subjects 6)
;(randomize-treatments #:list treatments #:forSubjectCount number-of-subjects)
Usage:
(randomize-treatments #:list treatments #:forSubjectCount number-of-subjects)
given a list of treatments and an integer number of subjects, call '''randomize-treatments''':
> (define treatments '(drug1 drug2 drug3 drug4))
> (define number-of-subjects 6)
> (randomize-treatments #:list treatments #:forSubjectCount number-of-subjects)
6 drug2 drug1 drug3 drug4
5 drug3 drug4 drug2 drug1
4 drug3 drug2 drug1 drug4
3 drug1 drug4 drug3 drug2
2 drug2 drug3 drug4 drug1
1 drug4 drug2 drug3 drug1
done
>
Here is the racket file, randomize-treatments.rkt. The source listing is below.
#lang racket
; randomize-treatments
; given a list of treatments and a number of subjects,
; prints out a list of treatments for each subject
; see usage example at bottom
(define shuffle ; Returns a randomly re-ordered copy of list.
(lambda (list)
(if (< (length list) 2)
list
(let ((item (list-ref list (random (length list)))))
(cons item (shuffle (remove item list)))))))
(define display-list-with-tabs; prints a list with tabs between members
(lambda (list)
(if (> (length list) 0)
(begin
(display (car list))
(if (> (length (cdr list)) 0)
(display "\t")
#f)
(display-list-with-tabs (cdr list)))
(displayln "")
)))
(define randomize-treatments
; given a list of treatments and a number of subjects,
; prints out a list of treatments for each subject
(lambda (#:list rx-list #:forSubjectCount n )
(if (> n 0)
(begin
(display n)(display "\t")
(display-list-with-tabs (shuffle rx-list))
(randomize-treatments #:list rx-list #:forSubjectCount (sub1 n)))
(displayln 'done)
)))
; usage
;(define treatments '(drug1 drug2 drug3 drug4))
;(define number-of-subjects 6)
;(randomize-treatments #:list treatments #:forSubjectCount number-of-subjects)