{"id":286,"date":"2023-07-03T09:00:00","date_gmt":"2023-07-03T07:00:00","guid":{"rendered":"https:\/\/arnaud.collignan.net\/blog\/?p=286"},"modified":"2023-09-30T09:26:48","modified_gmt":"2023-09-30T07:26:48","slug":"arrondis-aleatoires","status":"publish","type":"post","link":"https:\/\/arnaud.collignan.net\/blog\/2023\/07\/03\/arrondis-aleatoires\/","title":{"rendered":"Arrondis al\u00e9atoires ?"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">Nous l&#8217;avons tous appris en petite \u00e9cole : lorsque l&#8217;on arrondi un nombre \u00e0 l&#8217;entier le plus proche, on arrondi par d\u00e9faut (au-dessous) de .0 \u00e0 .4, et on arrondi par exc\u00e8s (au-dessus) de .5 \u00e0 .9. Mais aviez-vous remarqu\u00e9 que l&#8217;arrondi de .5 par exc\u00e8s est une <strong>convention <\/strong>?<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">En effet, si l&#8217;on  prend par exemple 8.5, c&#8217;est un nombre qui se trouve \u00e0 \u00e9gale distance de 8 (-0.5) et de 9 (+0.5).<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">C&#8217;est ainsi que j&#8217;ai d\u00e9couvert que certains langage de programmation <strong>ne respectent pas forc\u00e9ment la convention<\/strong> (cf. liens ci-dessous en cr\u00e9dits). Le Python, par exemple, va arrondir .5 par exc\u00e8s si le chiffre qui pr\u00e9c\u00e8de la virgule est impair, et par d\u00e9faut s&#8217;il est pair. En pratique, 8.5 sera arrondi \u00e0 8, tandis que 7.5 est \u00e9galement arrondi \u00e0 8 ! Troublant.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">J&#8217;ai moi-m\u00eame v\u00e9rifi\u00e9 avec MATLAB (image ci-dessous), mais ce dernier respecte bien la convention.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full is-resized\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/arnaud.collignan.net\/blog\/wp-content\/uploads\/2023\/06\/image.png\" alt=\"\" class=\"wp-image-288\" width=\"456\" height=\"194\" srcset=\"https:\/\/arnaud.collignan.net\/blog\/wp-content\/uploads\/2023\/06\/image.png 911w, https:\/\/arnaud.collignan.net\/blog\/wp-content\/uploads\/2023\/06\/image-300x128.png 300w, https:\/\/arnaud.collignan.net\/blog\/wp-content\/uploads\/2023\/06\/image-768x327.png 768w\" sizes=\"auto, (max-width: 456px) 100vw, 456px\" \/><figcaption class=\"wp-element-caption\">Test\u00e9 sous MATLAB<\/figcaption><\/figure>\n<\/div>\n\n\n<p class=\"wp-block-paragraph\">En conclusion, si vous manipulez du code et proc\u00e9dez \u00e0 des arrondis, m\u00e9fiez-vous.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Nous l&#8217;avons tous appris en petite \u00e9cole : lorsque l&#8217;on arrondi un nombre \u00e0 l&#8217;entier le plus proche, on arrondi par d\u00e9faut (au-dessous) de .0&#8230;<\/p>\n<div class=\"more-link-wrapper\"><a class=\"more-link\" href=\"https:\/\/arnaud.collignan.net\/blog\/2023\/07\/03\/arrondis-aleatoires\/\">Lire la suite&#8230;<span class=\"screen-reader-text\">Arrondis al\u00e9atoires ?<\/span><\/a><\/div>\n","protected":false},"author":1,"featured_media":289,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[55],"tags":[52,83,66,6],"class_list":["post-286","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-mathematiques","tag-mathematiques","tag-matlab","tag-programmation","tag-reflexion","entry"],"acf":{"auteur_de_limage":"Markus Spiske","url_de_lauteur_de_limage":"https:\/\/www.pexels.com\/fr-fr\/photo\/codes-sur-le-tilt-shift-lens-2004161\/","source":"Benjamin Dubreau","url_de_la_source":"https:\/\/www.linkedin.com\/posts\/benjamin-dubreu-data_python-data-datascience-activity-7075405712406781953-Y4tc","bibliographie":"Documentation Python","url_de_la_bibliographie":"https:\/\/www.w3schools.com\/python\/trypython.asp?filename=demo_ref_round2"},"_links":{"self":[{"href":"https:\/\/arnaud.collignan.net\/blog\/wp-json\/wp\/v2\/posts\/286","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/arnaud.collignan.net\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/arnaud.collignan.net\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/arnaud.collignan.net\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/arnaud.collignan.net\/blog\/wp-json\/wp\/v2\/comments?post=286"}],"version-history":[{"count":9,"href":"https:\/\/arnaud.collignan.net\/blog\/wp-json\/wp\/v2\/posts\/286\/revisions"}],"predecessor-version":[{"id":297,"href":"https:\/\/arnaud.collignan.net\/blog\/wp-json\/wp\/v2\/posts\/286\/revisions\/297"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/arnaud.collignan.net\/blog\/wp-json\/wp\/v2\/media\/289"}],"wp:attachment":[{"href":"https:\/\/arnaud.collignan.net\/blog\/wp-json\/wp\/v2\/media?parent=286"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/arnaud.collignan.net\/blog\/wp-json\/wp\/v2\/categories?post=286"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/arnaud.collignan.net\/blog\/wp-json\/wp\/v2\/tags?post=286"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}