建立符号变量a111.zip_灰色预测_matlab例程_数值算法/人工智能下载-pudn.com

<html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta charset="utf-8"> <meta name="generator" content="pdf2htmlEX"> <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1"> <link rel="stylesheet" href="https://static.pudn.com/base/css/base.min.css"> <link rel="stylesheet" href="https://static.pudn.com/base/css/fancy.min.css"> <link rel="stylesheet" href="https://static.pudn.com/prod/directory_preview_static/6269914f0990925c044d3afe/raw.css"> <script src="https://static.pudn.com/base/js/compatibility.min.js"></script> <script src="https://static.pudn.com/base/js/pdf2htmlEX.min.js"></script> <script> try{ pdf2htmlEX.defaultViewer = new pdf2htmlEX.Viewer({}); }catch(e){} </script> <title></title> </head> <body> <div id="sidebar" style="display: none"> <div id="outline"> </div> </div> <div id="pf1" class="pf w0 h0" data-page-no="1"><div class="pc pc1 w0 h0"><img class="bi x0 y0 w1 h1" alt="" src="https://static.pudn.com/prod/directory_preview_static/6269914f0990925c044d3afe/bg1.jpg"><div class="c x0 y1 w2 h2"><div class="t m0 x1 h3 y2 ff1 fs0 fc0 sc0 ls0 ws0">%<span class="ff2">徐<span class="_ _0"> </span></span>PZ -----SDJU---<span class="ff2">禁止转发</span></div><div class="t m0 x1 h3 y3 ff1 fs0 fc0 sc0 ls0 ws0">%<span class="ff2">建立符号变量<span class="_ _0"> </span></span>a(<span class="ff2">发展系数</span>)<span class="ff2">和<span class="_ _0"> </span></span>b(<span class="ff2">灰作用量</span>)</div><div class="t m0 x1 h4 y4 ff1 fs0 fc0 sc0 ls0 ws0">syms a b;</div><div class="t m0 x1 h4 y5 ff1 fs0 fc0 sc0 ls0 ws0">c = [a b]';</div><div class="t m0 x1 h3 y6 ff1 fs0 fc0 sc0 ls0 ws0">%<span class="ff2">原始数列 </span>A</div><div class="t m0 x1 h4 y7 ff1 fs0 fc0 sc0 ls0 ws0">A = [174<span class="_ _1"> </span>179<span class="_ _2"> </span>183<span class="_ _2"> </span>189<span class="_ _2"> </span>207<span class="_ _2"> </span>234<span class="_ _2"> </span>220.5 256<span class="_ _3"> </span>270<span class="_ _2"> </span>285];</div><div class="t m0 x1 h4 y8 ff1 fs0 fc0 sc0 ls0 ws0">n = length(A);</div><div class="t m0 x1 h3 y9 ff1 fs0 fc0 sc0 ls0 ws0">%<span class="ff2">对原始数列 </span>A <span class="ff2">做累加得到数列 </span>B</div><div class="t m0 x1 h4 ya ff1 fs0 fc0 sc0 ls0 ws0">B = cumsum(A);</div><div class="t m0 x1 h3 yb ff1 fs0 fc0 sc0 ls0 ws0">%<span class="ff2">对数列 </span>B <span class="ff2">做紧邻均值生成</span></div><div class="t m0 x1 h4 yc ff1 fs0 fc0 sc0 ls0 ws0">for i = 2:n</div><div class="t m0 x1 h4 yd ff1 fs0 fc0 sc0 ls0 ws0"> C(i) = (B(i) + B(i - 1))/2; </div><div class="t m0 x1 h4 ye ff1 fs0 fc0 sc0 ls0 ws0">end</div><div class="t m0 x1 h4 yf ff1 fs0 fc0 sc0 ls0 ws0">C(1) = [];</div><div class="t m0 x1 h3 y10 ff1 fs0 fc0 sc0 ls0 ws0">%<span class="ff2">构造数据矩阵 </span></div><div class="t m0 x1 h4 y11 ff1 fs0 fc0 sc0 ls0 ws0">B = [-C;ones(1,n-1)];</div><div class="t m0 x1 h4 y12 ff1 fs0 fc0 sc0 ls0 ws0">Y = A; Y(1) = []; Y = Y';</div><div class="t m0 x1 h3 y13 ff1 fs0 fc0 sc0 ls0 ws0">%<span class="ff2">使用最小二乘法计算参数 </span>a(<span class="ff2">发展系数</span>)<span class="ff2">和<span class="_ _0"> </span></span>b(<span class="ff2">灰作用量</span>)</div><div class="t m0 x1 h4 y14 ff1 fs0 fc0 sc0 ls0 ws0">c = inv(B*B')*B*Y<span class="_ _4"></span>;</div><div class="t m0 x1 h4 y15 ff1 fs0 fc0 sc0 ls0 ws0">c = c';</div><div class="t m0 x1 h4 y16 ff1 fs0 fc0 sc0 ls0 ws0">a = c(1); b = c(2);</div><div class="t m0 x1 h3 y17 ff1 fs0 fc0 sc0 ls0 ws0">%<span class="ff2">预测后续数据</span></div><div class="t m0 x1 h4 y18 ff1 fs0 fc0 sc0 ls0 ws0">F = []; F(1) = A(1);</div><div class="t m0 x1 h4 y19 ff1 fs0 fc0 sc0 ls0 ws0">for i = 2:(n+5)</div><div class="t m0 x1 h4 y1a ff1 fs0 fc0 sc0 ls0 ws0"> F(i) = (A(1)-b/a)<span class="_ _5"></span>/e<span class="_ _5"></span>xp(a*(i-1))+ b/a;</div><div class="t m0 x1 h4 y1b ff1 fs0 fc0 sc0 ls0 ws0">end</div><div class="t m0 x1 h3 y1c ff1 fs0 fc0 sc0 ls0 ws0">%<span class="ff2">对数列 </span>F <span class="ff2">累减还原</span>,<span class="ff2">得到预测出的数据</span></div><div class="t m0 x1 h4 y1d ff1 fs0 fc0 sc0 ls0 ws0">G = []; G(1) = A(1);</div><div class="t m0 x1 h4 y1e ff1 fs0 fc0 sc0 ls0 ws0">for i = 2:(n+5)</div><div class="t m0 x1 h3 y1f ff1 fs0 fc0 sc0 ls0 ws0"> G(i) = F(i) - F(i-1); %<span class="ff2">得到预测出来的数据</span></div><div class="t m0 x1 h4 y20 ff1 fs0 fc0 sc0 ls0 ws0">end</div><div class="t m0 x1 h3 y21 ff1 fs0 fc0 sc0 ls0 ws0">disp('<span class="ff2">预测数据为：</span>');</div><div class="t m0 x1 h4 y22 ff1 fs0 fc0 sc0 ls0 ws0">G</div><div class="t m0 x1 h3 y23 ff1 fs0 fc0 sc0 ls0 ws0">%<span class="ff2">模型检验</span></div><div class="t m0 x1 h3 y24 ff1 fs0 fc0 sc0 ls0 ws0">%<span class="ff2">模型检验</span></div></div></div><div class="pi" data-data='{"ctm":[1.611850,0.000000,0.000000,1.611850,0.000000,0.000000]}'></div></div> </body> </html>