{"id":4375,"date":"2021-02-08T06:30:14","date_gmt":"2021-02-08T06:30:14","guid":{"rendered":"https:\/\/www.aiproblog.com\/index.php\/2021\/02\/08\/more-surprising-math-images\/"},"modified":"2021-02-08T06:30:14","modified_gmt":"2021-02-08T06:30:14","slug":"more-surprising-math-images","status":"publish","type":"post","link":"https:\/\/www.aiproblog.com\/index.php\/2021\/02\/08\/more-surprising-math-images\/","title":{"rendered":"More Surprising Math Images"},"content":{"rendered":"<p>Author: Vincent Granville<\/p>\n<div>\n<p>This a follow up to my previous article <a href=\"https:\/\/www.datasciencecentral.com\/profiles\/blogs\/beautiful-mathematical-images\" target=\"_blank\" rel=\"noopener\">here<\/a>, where you can find additional, very different images, the theory behind it, and relevance to machine learning techniques. What is surprising is that all these images were produced with a formula with a single parameter <em>\u03bb<\/em>, and they look very different depending on the value of <em>\u03bb<\/em>. More precisely, they are generated using the following recursion:<\/p>\n<p style=\"text-align: center;\"><em>x<\/em><span style=\"font-size: 8pt;\"><em>n<\/em>+1<\/span><span>\u00a0<\/span>=<span>\u00a0<\/span><em>x<span style=\"font-size: 8pt;\">n<\/span><\/em><span>\u00a0<\/span>+\u00a0<em>\u03bb<\/em><span>\u00a0<\/span>sin(<em>y<span style=\"font-size: 8pt;\">n<\/span><\/em>),<\/p>\n<p style=\"text-align: center;\"><em>y<\/em><span style=\"font-size: 8pt;\"><em>n<\/em>+1<\/span><span>\u00a0<\/span>=<span>\u00a0<\/span><em>x<span style=\"font-size: 8pt;\">n<\/span><\/em><span>\u00a0<\/span>+\u00a0<em>\u03bb<\/em><span>\u00a0<\/span>sin(<em>x<span style=\"font-size: 8pt;\">n<\/span><\/em>),<\/p>\n<p>with initial conditions <em>x<\/em><span style=\"font-size: 8pt;\">0<\/span>, <em>y<\/em><span style=\"font-size: 8pt;\">0<\/span>.\u00a0<\/p>\n<p>Seven different groups of three images are displayed. In each group, the leftmost image, a scatterplot (in blue) corresponds to the orbit of (<em>x<span style=\"font-size: 8pt;\">n<\/span><\/em>, <em>y<span style=\"font-size: 8pt;\">n<\/span><\/em>) in two dimensions, given the initial conditions. The central images features <em>x<span style=\"font-size: 8pt;\">n<\/span><\/em> and <em>y<span style=\"font-size: 8pt;\">n<\/span><\/em> as two time series, with <em>x<span style=\"font-size: 8pt;\">n<\/span><\/em> in blue and <em>y<span style=\"font-size: 8pt;\">n<\/span><\/em> in red. In both cases, 20,000 iterations are used. The rightmost image is the same as the leftmost one, except that only the first 25 iterations are displayed, and a green curve connects the 25 dots, to show how the orbit looks like at the beginning. The initial vector (<em>x<\/em><span style=\"font-size: 8pt;\">0<\/span>, <em>y<\/em><span style=\"font-size: 8pt;\">0<\/span>) is not included in that image.<\/p>\n<\/p>\n<p><a href=\"https:\/\/storage.ning.com\/topology\/rest\/1.0\/file\/get\/8530324885?profile=original\" target=\"_blank\" rel=\"noopener\"><img decoding=\"async\" src=\"https:\/\/storage.ning.com\/topology\/rest\/1.0\/file\/get\/8530324885?profile=RESIZE_710x\" width=\"700\" class=\"align-center\"><\/a><\/p>\n<p style=\"text-align: center;\"><strong>Figure 1<\/strong>: <em>x<span style=\"font-size: 8pt;\">0<\/span> = 1, y<span style=\"font-size: 8pt;\">0<\/span> = 4,\u00a0\u03bb = 0.04<\/em><\/p>\n<p style=\"text-align: center;\">\n<p><a href=\"https:\/\/storage.ning.com\/topology\/rest\/1.0\/file\/get\/8530326887?profile=original\" target=\"_blank\" rel=\"noopener\"><img decoding=\"async\" src=\"https:\/\/storage.ning.com\/topology\/rest\/1.0\/file\/get\/8530326887?profile=RESIZE_710x\" width=\"700\" class=\"align-center\"><\/a><\/p>\n<p style=\"text-align: center;\"><strong>Figure 2<\/strong>: <em>x<span style=\"font-size: 8pt;\">0<\/span> = 1, y<span style=\"font-size: 8pt;\">0<\/span> = 4,\u00a0\u03bb = 0.06<\/em><\/p>\n<p style=\"text-align: center;\">\n<p style=\"text-align: center;\"><a href=\"https:\/\/storage.ning.com\/topology\/rest\/1.0\/file\/get\/8530323258?profile=original\" target=\"_blank\" rel=\"noopener\"><img decoding=\"async\" src=\"https:\/\/storage.ning.com\/topology\/rest\/1.0\/file\/get\/8530323258?profile=RESIZE_710x\" width=\"700\" class=\"align-center\"><\/a><\/p>\n<p style=\"text-align: center;\"><strong>Figure 3<\/strong>: <em>x<span style=\"font-size: 8pt;\">0<\/span> = 3, y<span style=\"font-size: 8pt;\">0<\/span> = 4,\u00a0\u03bb = 1.5<\/em><\/p>\n<\/p>\n<p><a href=\"https:\/\/storage.ning.com\/topology\/rest\/1.0\/file\/get\/8530331493?profile=original\" target=\"_blank\" rel=\"noopener\"><img decoding=\"async\" src=\"https:\/\/storage.ning.com\/topology\/rest\/1.0\/file\/get\/8530331493?profile=RESIZE_710x\" width=\"700\" class=\"align-center\"><\/a><\/p>\n<p style=\"text-align: center;\"><strong>Figure 4<\/strong>: <em>x<span style=\"font-size: 8pt;\">0<\/span> = 56, y<span style=\"font-size: 8pt;\">0<\/span> = 4,\u00a0\u03bb = 0.04<\/em><\/p>\n<p style=\"text-align: center;\">\n<p><a href=\"https:\/\/storage.ning.com\/topology\/rest\/1.0\/file\/get\/8530366692?profile=original\" target=\"_blank\" rel=\"noopener\"><img decoding=\"async\" src=\"https:\/\/storage.ning.com\/topology\/rest\/1.0\/file\/get\/8530366692?profile=RESIZE_710x\" width=\"700\" class=\"align-center\"><\/a><\/p>\n<p style=\"text-align: center;\"><strong>Figure 5<\/strong>: <em>x<span style=\"font-size: 8pt;\">0<\/span> = 2, y<span style=\"font-size: 8pt;\">0<\/span> = 4,\u00a0\u03bb = 10<\/em><\/p>\n<\/p>\n<p><a href=\"https:\/\/storage.ning.com\/topology\/rest\/1.0\/file\/get\/8530385678?profile=original\" target=\"_blank\" rel=\"noopener\"><img decoding=\"async\" src=\"https:\/\/storage.ning.com\/topology\/rest\/1.0\/file\/get\/8530385678?profile=RESIZE_710x\" width=\"700\" class=\"align-center\"><\/a><\/p>\n<p style=\"text-align: center;\"><strong>Figure 6<\/strong>: <em>x<span>0<\/span> = 1, y<span>0<\/span> = 4,\u00a0\u03bb = 2.5<\/em><\/p>\n<\/p>\n<p><a href=\"https:\/\/storage.ning.com\/topology\/rest\/1.0\/file\/get\/8530386883?profile=original\" target=\"_blank\" rel=\"noopener\"><img decoding=\"async\" src=\"https:\/\/storage.ning.com\/topology\/rest\/1.0\/file\/get\/8530386883?profile=RESIZE_710x\" width=\"700\" class=\"align-center\"><\/a><\/p>\n<p style=\"text-align: center;\"><strong>Figure 7<\/strong>: <em>x<span style=\"font-size: 8pt;\">0<\/span> = 3, y<span style=\"font-size: 8pt;\">0<\/span> = 4,\u00a0\u03bb = 2<\/em><\/p>\n<\/p>\n<p><em><strong>About the author<\/strong>:\u00a0 Vincent Granville is a d<span class=\"lt-line-clamp__raw-line\">ata science pioneer, mathematician, book author (Wiley), patent owner, former post-doc at Cambridge University, former VC-funded executive, with 20+ years of corporate experience including CNET, NBC, Visa, Wells Fargo, Microsoft, eBay. Vincent also founded and co-founded a few start-ups, including one with a successful exit (Data Science Central acquired by Tech Target).<\/span>\u00a0He is also the founder and investor in<span>\u00a0<\/span><a href=\"https:\/\/www.parisrestaurantandbar.com\/blog\" target=\"_blank\" rel=\"noopener\">Paris Restaurant<\/a><span>\u00a0<\/span>in Anacortes, WA. You can access Vincent&#8217;s articles and books,<span>\u00a0<\/span><a href=\"https:\/\/www.datasciencecentral.com\/profiles\/blogs\/my-data-science-machine-learning-and-related-articles\" target=\"_blank\" rel=\"noopener\">here<\/a>.<\/em><\/p>\n<\/div>\n<p><a href=\"https:\/\/www.datasciencecentral.com\/xn\/detail\/6448529:BlogPost:1022670\">Go to Source<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Author: Vincent Granville This a follow up to my previous article here, where you can find additional, very different images, the theory behind it, and [&hellip;] <span class=\"read-more-link\"><a class=\"read-more\" href=\"https:\/\/www.aiproblog.com\/index.php\/2021\/02\/08\/more-surprising-math-images\/\">Read More<\/a><\/span><\/p>\n","protected":false},"author":1,"featured_media":472,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_bbp_topic_count":0,"_bbp_reply_count":0,"_bbp_total_topic_count":0,"_bbp_total_reply_count":0,"_bbp_voice_count":0,"_bbp_anonymous_reply_count":0,"_bbp_topic_count_hidden":0,"_bbp_reply_count_hidden":0,"_bbp_forum_subforum_count":0,"footnotes":""},"categories":[26],"tags":[],"_links":{"self":[{"href":"https:\/\/www.aiproblog.com\/index.php\/wp-json\/wp\/v2\/posts\/4375"}],"collection":[{"href":"https:\/\/www.aiproblog.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.aiproblog.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.aiproblog.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.aiproblog.com\/index.php\/wp-json\/wp\/v2\/comments?post=4375"}],"version-history":[{"count":0,"href":"https:\/\/www.aiproblog.com\/index.php\/wp-json\/wp\/v2\/posts\/4375\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.aiproblog.com\/index.php\/wp-json\/wp\/v2\/media\/466"}],"wp:attachment":[{"href":"https:\/\/www.aiproblog.com\/index.php\/wp-json\/wp\/v2\/media?parent=4375"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.aiproblog.com\/index.php\/wp-json\/wp\/v2\/categories?post=4375"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.aiproblog.com\/index.php\/wp-json\/wp\/v2\/tags?post=4375"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}