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(in-package #:containers)
(eval-when (:compile-toplevel :load-toplevel :execute)
(use-package (find-package 'cl-variates)
(find-package 'cl-containers)))
(defmethod sample-item ((container t)
(generator variates:random-number-generation-mixin))
(sample-item container (variates:random-number-generator generator)))
(defmethod sample-item ((container iteratable-container-mixin)
(generator variates:basic-random-number-generator))
(let ((index (variates:integer-random generator 0 (1- (size container)))))
(nth-item container index)))
(defmethod sample-item ((container sequence)
(generator variates:basic-random-number-generator))
(declare (inline sample-element))
(sample-element container generator))
(defmethod nth-item ((container iteratable-container-mixin) index)
;; possibly slow but servicable method
(iterate-container
container
(lambda (elt)
(when (minusp (decf index))
(return-from nth-item elt))))
(error "Index ~D out of range for container ~A" index container))
(defmethod sample-element ((container t)
(generator variates:random-number-generation-mixin))
(sample-element container (variates:random-number-generator generator)))
(defmethod sample-element ((container (eql nil))
(generator variates:basic-random-number-generator))
(values nil))
(defmethod sample-element ((container iteratable-container-mixin)
(generator variates:basic-random-number-generator))
(let ((element (variates:integer-random generator 0 (1- (size container)))))
(nth-element container element)))
(defmethod sample-element ((container sequence)
(generator variates:basic-random-number-generator))
(let ((element (variates:integer-random generator 0 (1- (size container)))))
(nth-element container element)))
(defmethod sample-unique-elements ((container t)
(generator variates:random-number-generation-mixin)
(count integer))
(sample-unique-elements
container (variates:random-number-generator generator) count))
(defmethod sample-unique-elements ((container iteratable-container-mixin)
(generator variates:basic-random-number-generator)
(count integer))
(%sample-unique-elements container generator count)
#+Old
(loop for bit across (variates:select-sample generator count (size container))
for index = 0 then (1+ index)
unless (zerop bit) collect
(nth-element container index)))
(defmethod sample-unique-elements ((container list)
(generator variates:basic-random-number-generator)
(count integer))
(%sample-unique-elements container generator count)
#+Old
(loop for bit across (variates:select-sample generator count (size container))
for index = 0 then (1+ index)
unless (zerop bit) collect
(nth-element container index)))
(defmethod sample-unique-elements ((container array)
(generator variates:basic-random-number-generator)
(count integer))
(%sample-unique-elements container generator count)
#+Old
(loop for bit across (variates:select-sample generator count (size container))
for index = 0 then (1+ index)
unless (zerop bit) collect
(nth-element container index)))
#+SLOWER
;;?? Gary King 2005-11-04: intuitively, this should win because it bails out
;; early. However, loop must be doing something clever and so it doesn't.
(defun %sample-unique-elements (container generator count)
(let ((result nil))
(loop for bit across (variates:select-sample generator count (size container))
for index = 0 then (1+ index)
unless (zerop bit) do
(decf count)
(push (nth-element container index) result)
when (zerop count) do
(return))
(nreverse result)))
(defun %sample-unique-elements (container generator count)
(let ((result nil))
(loop for bit across (variates:select-sample generator count (size container))
for index = 0 then (1+ index)
unless (zerop bit) do
(push (nth-element container index) result)
)
(nreverse result)))
#+Test
(let ((l (collect-elements (make-generator :start 0 :end 1000))))
(timeit (:report t)
(loop repeat 1000 do
(sample-unique-elements l *random-generator* 10))))
(defmethod sample-elements ((container t)
(generator variates:random-number-generation-mixin)
(count integer))
(sample-elements container (variates:random-number-generator generator) count))
(defmethod sample-elements ((container iteratable-container-mixin)
(generator variates:basic-random-number-generator)
(count integer))
(loop repeat count collect
(sample-element container generator)))
(defmethod sample-elements ((container list)
(generator variates:basic-random-number-generator)
(count integer))
(loop repeat count collect
(sample-element container generator)))
(defun safe-sample-unique-elements (container generator count)
(if (length-at-most-p container count)
(collect-elements container)
(sample-unique-elements container generator count)))
#+Test
(let ((c (make-container 'list-container
:initial-contents (loop for i from 0 to 10 collect i))))
(containers::sample-unique-elements c variates:*random-generator* 5))
#+Test
(let ((c (make-container 'array-container :dimensions '(5 5))))
(loop for i from 0 to 4 do
(loop for j from 0 to 4 do
(setf (item-at c i j) (* (1+ i) (1+ j)))))
(containers::sample-unique-elements c variates:*random-generator* 5))
(defmethod variates:shuffle-elements! ((container abstract-container)
&key (generator variates:*random-generator*)
(times 0 times-supplied?))
(let ((size (1- (size container))))
(dotimes (i (if times-supplied? times (* 2 size)))
(rotatef (nth-element container (variates:integer-random generator 0 size))
(nth-element container (variates:integer-random generator 0 size))))))
(defmethod variates:shuffle-elements! ((container uses-contents-mixin)
&rest args)
(declare (dynamic-extent args))
(apply #'variates:shuffle-elements! (contents container) args)
container)
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