{"id":194,"date":"2023-02-24T21:26:46","date_gmt":"2023-02-24T13:26:46","guid":{"rendered":"http:\/\/47.93.1.71\/?p=194"},"modified":"2023-02-24T21:55:11","modified_gmt":"2023-02-24T13:55:11","slug":"python%e8%bf%9b%e8%a1%8c%e5%ae%9e%e6%95%b0fft","status":"publish","type":"post","link":"https:\/\/blog.changelife.top\/index.php\/2023\/02\/24\/python%e8%bf%9b%e8%a1%8c%e5%ae%9e%e6%95%b0fft\/","title":{"rendered":"python\u8fdb\u884c\u5b9e\u6570fft"},"content":{"rendered":"\n<div class=\"wp-block-kevinbatdorf-code-block-pro\" style=\"font-size:.875rem;line-height:1.25rem\"><span style=\"display:block;padding:16px 0 0 16px;margin-bottom:-1px;width:100%;text-align:left;background-color:#2e3440ff\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"54\" height=\"14\" viewBox=\"0 0 54 14\"><g fill=\"none\" fill-rule=\"evenodd\" transform=\"translate(1 1)\"><circle cx=\"6\" cy=\"6\" r=\"6\" fill=\"#FF5F56\" stroke=\"#E0443E\" stroke-width=\".5\"><\/circle><circle cx=\"26\" cy=\"6\" r=\"6\" fill=\"#FFBD2E\" stroke=\"#DEA123\" stroke-width=\".5\"><\/circle><circle cx=\"46\" cy=\"6\" r=\"6\" fill=\"#27C93F\" stroke=\"#1AAB29\" stroke-width=\".5\"><\/circle><\/g><\/svg><\/span><span role=\"button\" tabindex=\"0\" data-code=\"from scipy.fft import fft,fftfreq,rfft,hfft,rfftfreq\nimport numpy as np\nimport matplotlib.pyplot as plt\nN = 3001\nxf=np.zeros((N,2))\n#print(xf)\n\n#\u751f\u6210\u6ce2\u5f62\nxf[:,0]=np.linspace(0,10*np.pi,N)\n#print(np.sin(xf[:,0]))\nxf[:,1]=np.sin(xf[:,0])\n#print(xf)\n\n#\nZ = rfft(xf[:,1])#\u5085\u91cc\u53f6\u53d8\u6362\n#print(type(Z))\n#print(Z)\nx=rfftfreq(N,10*np.pi\/N)#\u83b7\u53d6\u5085\u91cc\u53f6\u53d8\u6362\u7684\u6a2a\u5750\u6807(\u6570\u91cf\uff0c\u95f4\u9694\uff09\uff08\u751f\u6210\u7684\u6570\u91cf\u662fN\/\/2)\nk=plt.plot(x, np.abs(Z))\nplt.show()\" style=\"color:#d8dee9ff;display:none\" aria-label=\"Copy\" class=\"code-block-pro-copy-button\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" style=\"width:24px;height:24px\" fill=\"none\" viewBox=\"0 0 24 24\" stroke=\"currentColor\" stroke-width=\"2\"><path class=\"with-check\" stroke-linecap=\"round\" stroke-linejoin=\"round\" d=\"M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2m-6 9l2 2 4-4\"><\/path><path class=\"without-check\" stroke-linecap=\"round\" stroke-linejoin=\"round\" d=\"M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2\"><\/path><\/svg><\/span><pre class=\"shiki nord\" style=\"background-color: #2e3440ff\"><code><span class=\"line\"><span style=\"color: #81A1C1\">from<\/span><span style=\"color: #D8DEE9FF\"> scipy<\/span><span style=\"color: #ECEFF4\">.<\/span><span style=\"color: #D8DEE9FF\">fft <\/span><span style=\"color: #81A1C1\">import<\/span><span style=\"color: #D8DEE9FF\"> fft<\/span><span style=\"color: #ECEFF4\">,<\/span><span style=\"color: #D8DEE9FF\">fftfreq<\/span><span style=\"color: #ECEFF4\">,<\/span><span style=\"color: #D8DEE9FF\">rfft<\/span><span style=\"color: #ECEFF4\">,<\/span><span style=\"color: #D8DEE9FF\">hfft<\/span><span style=\"color: #ECEFF4\">,<\/span><span style=\"color: #D8DEE9FF\">rfftfreq<\/span><\/span>\n<span class=\"line\"><span style=\"color: #81A1C1\">import<\/span><span style=\"color: #D8DEE9FF\"> numpy <\/span><span style=\"color: #81A1C1\">as<\/span><span style=\"color: #D8DEE9FF\"> np<\/span><\/span>\n<span class=\"line\"><span style=\"color: #81A1C1\">import<\/span><span style=\"color: #D8DEE9FF\"> matplotlib<\/span><span style=\"color: #ECEFF4\">.<\/span><span style=\"color: #D8DEE9FF\">pyplot <\/span><span style=\"color: #81A1C1\">as<\/span><span style=\"color: #D8DEE9FF\"> plt<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">N <\/span><span style=\"color: #81A1C1\">=<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #B48EAD\">3001<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">xf<\/span><span style=\"color: #81A1C1\">=<\/span><span style=\"color: #D8DEE9FF\">np<\/span><span style=\"color: #ECEFF4\">.<\/span><span style=\"color: #88C0D0\">zeros<\/span><span style=\"color: #ECEFF4\">((<\/span><span style=\"color: #D8DEE9FF\">N<\/span><span style=\"color: #ECEFF4\">,<\/span><span style=\"color: #B48EAD\">2<\/span><span style=\"color: #ECEFF4\">))<\/span><\/span>\n<span class=\"line\"><span style=\"color: #616E88\">#print(xf)<\/span><\/span>\n<span class=\"line\"><\/span>\n<span class=\"line\"><span style=\"color: #616E88\">#\u751f\u6210\u6ce2\u5f62<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">xf<\/span><span style=\"color: #ECEFF4\">[:,<\/span><span style=\"color: #B48EAD\">0<\/span><span style=\"color: #ECEFF4\">]<\/span><span style=\"color: #81A1C1\">=<\/span><span style=\"color: #D8DEE9FF\">np<\/span><span style=\"color: #ECEFF4\">.<\/span><span style=\"color: #88C0D0\">linspace<\/span><span style=\"color: #ECEFF4\">(<\/span><span style=\"color: #B48EAD\">0<\/span><span style=\"color: #ECEFF4\">,<\/span><span style=\"color: #B48EAD\">10<\/span><span style=\"color: #81A1C1\">*<\/span><span style=\"color: #D8DEE9FF\">np<\/span><span style=\"color: #ECEFF4\">.<\/span><span style=\"color: #D8DEE9FF\">pi<\/span><span style=\"color: #ECEFF4\">,<\/span><span style=\"color: #D8DEE9FF\">N<\/span><span style=\"color: #ECEFF4\">)<\/span><\/span>\n<span class=\"line\"><span style=\"color: #616E88\">#print(np.sin(xf[:,0]))<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">xf<\/span><span style=\"color: #ECEFF4\">[:,<\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #ECEFF4\">]<\/span><span style=\"color: #81A1C1\">=<\/span><span style=\"color: #D8DEE9FF\">np<\/span><span style=\"color: #ECEFF4\">.<\/span><span style=\"color: #88C0D0\">sin<\/span><span style=\"color: #ECEFF4\">(<\/span><span style=\"color: #D8DEE9FF\">xf<\/span><span style=\"color: #ECEFF4\">[:,<\/span><span style=\"color: #B48EAD\">0<\/span><span style=\"color: #ECEFF4\">])<\/span><\/span>\n<span class=\"line\"><span style=\"color: #616E88\">#print(xf)<\/span><\/span>\n<span class=\"line\"><\/span>\n<span class=\"line\"><span style=\"color: #616E88\">#<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">Z <\/span><span style=\"color: #81A1C1\">=<\/span><span style=\"color: #D8DEE9FF\"> <\/span><span style=\"color: #88C0D0\">rfft<\/span><span style=\"color: #ECEFF4\">(<\/span><span style=\"color: #D8DEE9FF\">xf<\/span><span style=\"color: #ECEFF4\">[:,<\/span><span style=\"color: #B48EAD\">1<\/span><span style=\"color: #ECEFF4\">])<\/span><span style=\"color: #616E88\">#\u5085\u91cc\u53f6\u53d8\u6362<\/span><\/span>\n<span class=\"line\"><span style=\"color: #616E88\">#print(type(Z))<\/span><\/span>\n<span class=\"line\"><span style=\"color: #616E88\">#print(Z)<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">x<\/span><span style=\"color: #81A1C1\">=<\/span><span style=\"color: #88C0D0\">rfftfreq<\/span><span style=\"color: #ECEFF4\">(<\/span><span style=\"color: #D8DEE9FF\">N<\/span><span style=\"color: #ECEFF4\">,<\/span><span style=\"color: #B48EAD\">10<\/span><span style=\"color: #81A1C1\">*<\/span><span style=\"color: #D8DEE9FF\">np<\/span><span style=\"color: #ECEFF4\">.<\/span><span style=\"color: #D8DEE9FF\">pi<\/span><span style=\"color: #81A1C1\">\/<\/span><span style=\"color: #D8DEE9FF\">N<\/span><span style=\"color: #ECEFF4\">)<\/span><span style=\"color: #616E88\">#\u83b7\u53d6\u5085\u91cc\u53f6\u53d8\u6362\u7684\u6a2a\u5750\u6807(\u6570\u91cf\uff0c\u95f4\u9694\uff09\uff08\u751f\u6210\u7684\u6570\u91cf\u662fN\/\/2)<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">k<\/span><span style=\"color: #81A1C1\">=<\/span><span style=\"color: #D8DEE9FF\">plt<\/span><span style=\"color: #ECEFF4\">.<\/span><span style=\"color: #88C0D0\">plot<\/span><span style=\"color: #ECEFF4\">(<\/span><span style=\"color: #D8DEE9FF\">x<\/span><span style=\"color: #ECEFF4\">,<\/span><span style=\"color: #D8DEE9FF\"> np<\/span><span style=\"color: #ECEFF4\">.<\/span><span style=\"color: #88C0D0\">abs<\/span><span style=\"color: #ECEFF4\">(<\/span><span style=\"color: #D8DEE9FF\">Z<\/span><span style=\"color: #ECEFF4\">))<\/span><\/span>\n<span class=\"line\"><span style=\"color: #D8DEE9FF\">plt<\/span><span style=\"color: #ECEFF4\">.<\/span><span style=\"color: #88C0D0\">show<\/span><span style=\"color: #ECEFF4\">()<\/span><\/span><\/code><\/pre><\/div>\n","protected":false},"excerpt":{"rendered":"","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6,9],"tags":[],"class_list":["post-194","post","type-post","status-publish","format-standard","hentry","category-python","category-windows"],"_links":{"self":[{"href":"https:\/\/blog.changelife.top\/index.php\/wp-json\/wp\/v2\/posts\/194","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.changelife.top\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.changelife.top\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.changelife.top\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.changelife.top\/index.php\/wp-json\/wp\/v2\/comments?post=194"}],"version-history":[{"count":2,"href":"https:\/\/blog.changelife.top\/index.php\/wp-json\/wp\/v2\/posts\/194\/revisions"}],"predecessor-version":[{"id":196,"href":"https:\/\/blog.changelife.top\/index.php\/wp-json\/wp\/v2\/posts\/194\/revisions\/196"}],"wp:attachment":[{"href":"https:\/\/blog.changelife.top\/index.php\/wp-json\/wp\/v2\/media?parent=194"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.changelife.top\/index.php\/wp-json\/wp\/v2\/categories?post=194"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.changelife.top\/index.php\/wp-json\/wp\/v2\/tags?post=194"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}