guile/test-suite/tests/random.test

;;;; random.test --- tests guile's uniform arrays     -*- scheme -*-
;;;;
;;;; Copyright 2013 Free Software Foundation, Inc.
;;;;
;;;; This library is free software; you can redistribute it and/or
;;;; modify it under the terms of the GNU Lesser General Public
;;;; License as published by the Free Software Foundation; either
;;;; version 3 of the License, or (at your option) any later version.
;;;;
;;;; This library is distributed in the hope that it will be useful,
;;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
;;;; Lesser General Public License for more details.
;;;;
;;;; You should have received a copy of the GNU Lesser General Public
;;;; License along with this library; if not, write to the Free Software
;;;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

(define-module (test-suite test-random)
  #:use-module ((system base compile) #:select (compile))
  #:use-module (test-suite lib)
  #:use-module (srfi srfi-4)
  #:use-module (srfi srfi-4 gnu)
  #:use-module ((ice-9 control) #:select (let/ec)))

; see strings.test, arrays.test.
(define exception:wrong-type-arg
  (cons #t "Wrong type"))

;;;
;;; random:normal-vector!
;;;

(with-test-prefix "random:normal-vector!"

  ;; FIXME need proper function test.

  (pass-if "non uniform"
    (let ((a (make-vector 4 0))
          (b (make-vector 4 0))
          (c (make-shared-array (make-vector 8 0)
                                (lambda (i) (list (+ 1 (* 2 i)))) 4)))
      (begin
        (random:normal-vector! b (random-state-from-platform))
        (random:normal-vector! c (random-state-from-platform))
        (and (not (equal? a b)) (not (equal? a c))))))

  (pass-if "uniform (f64)"
    (let ((a (make-f64vector 4 0))
          (b (make-f64vector 4 0))
          (c (make-shared-array (make-f64vector 8 0)
                                (lambda (i) (list (+ 1 (* 2 i)))) 4)))
      (begin
        (random:normal-vector! b (random-state-from-platform))
        (random:normal-vector! c (random-state-from-platform))
        (and (not (equal? a b)) (not (equal? a c))))))

  (pass-if "empty argument"
    (random:normal-vector! (vector) (random-state-from-platform))
    (random:normal-vector! (f64vector) (random-state-from-platform))
    #t))

;;;
;;; random:hollow-sphere!
;;;

(with-test-prefix "random:hollow-sphere!"

  (define (sqr a)
    (* a a))
  (define (norm a)
    (sqrt (+ (sqr (array-ref a 0)) (sqr (array-ref a 1)) (sqr (array-ref a 2)))))
  (define double-eps 1e-15)
  
  (pass-if "non uniform"
    (let ((a (transpose-array (make-array 0. 3 10) 1 0)))
      (let/ec exit
        (array-slice-for-each 1
          (lambda (a)
            (random:hollow-sphere! a)
            (if (> (magnitude (- 1 (norm a))) double-eps) (exit #f)))
          a)
        #t)))

  (pass-if "uniform (f64)"
    (let ((a (transpose-array (make-array 0. 3 10) 1 0)))
      (let/ec exit
        (array-slice-for-each 1
          (lambda (a)
            (random:hollow-sphere! a)
            (if (> (magnitude (- 1 (norm a))) double-eps) (exit #f)))
          a)
        #t)))

  (pass-if "empty argument"
    (random:hollow-sphere! (vector))
    (random:hollow-sphere! (f64vector))
    #t))