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小溪的空气

<p>一道BP神经网络的问题，用matlab实现</p><div class="O" vshape="_x0000_s1026"><div style="mso-line-spacing: &quot;80 20 0&quot;; mso-margin-left-alt: 216; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span style="COLOR: #006600; FONT-FAMILY: 宋体; mso-fareast-font-family: 宋体; mso-hansi-font-family: Arial;"><b>训练神经网络 </b></span></div><div style="mso-line-spacing: &quot;80 20 0&quot;; mso-margin-left-alt: 216; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span lang="EN-US" style="COLOR: #006600; mso-fareast-font-family: 宋体; mso-hansi-font-family: Arial; mso-fareast-language: ZH-CN;"><b>1)</b></span><span style="COLOR: #006600; FONT-FAMILY: 宋体; mso-fareast-font-family: 宋体; mso-hansi-font-family: Arial;"><b>训练集：</b></span><span style="COLOR: #006600; FONT-FAMILY: 宋体; mso-fareast-font-family: 宋体; mso-hansi-font-family: Arial;"><b><i>
                                        </i></b></span></div><div style="mso-line-spacing: &quot;80 20 0&quot;; mso-margin-left-alt: 216; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span lang="EN-US" style="COLOR: #006600; mso-fareast-font-family: 宋体; mso-hansi-font-family: Arial; mso-fareast-language: ZH-CN;"><b><i>X = 2*pi*rand(1,300); </i></b></span></div><div style="mso-line-spacing: &quot;80 20 0&quot;; mso-margin-left-alt: 216; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span lang="EN-US" style="COLOR: #006600; mso-fareast-font-family: 宋体; mso-hansi-font-family: Arial; mso-fareast-language: ZH-CN;"><b><i>Y = sin(X) + 0.2*randn(1,length(X)) </i></b></span></div><div style="mso-line-spacing: &quot;80 20 0&quot;; mso-margin-left-alt: 216; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span lang="EN-US" style="COLOR: #006600; mso-fareast-font-family: 宋体; mso-hansi-font-family: Arial; mso-fareast-language: ZH-CN;"><b><i>plot(X,Y,’+’)</i></b></span><span lang="EN-US" style="COLOR: #006600; FONT-FAMILY: 宋体; mso-fareast-font-family: 宋体; mso-hansi-font-family: Arial; mso-fareast-language: ZH-CN;"><b>
" B+ w. m9 B" T% U( G7 w" B, ^                                </b></span></div><div style="mso-line-spacing: &quot;80 20 0&quot;; mso-margin-left-alt: 216; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span style="COLOR: #006600; FONT-FAMILY: 宋体; mso-fareast-font-family: 宋体; mso-hansi-font-family: Arial;"><b>测试集：</b></span><span style="COLOR: #006600; FONT-FAMILY: 宋体; mso-fareast-font-family: 宋体; mso-hansi-font-family: Arial;"><b><i>
                                        </i></b></span></div><div style="mso-line-spacing: &quot;80 20 0&quot;; mso-margin-left-alt: 216; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span lang="EN-US" style="COLOR: #006600; mso-fareast-font-family: 宋体; mso-hansi-font-family: Arial; mso-fareast-language: ZH-CN;"><b><i>X2 = 2*pi*rand(1,300); </i></b></span></div><div style="mso-line-spacing: &quot;80 20 0&quot;; mso-margin-left-alt: 216; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span lang="EN-US" style="COLOR: #006600; mso-fareast-font-family: 宋体; mso-hansi-font-family: Arial; mso-fareast-language: ZH-CN;"><b><i>Y2 = sin(X2) + 0.2*randn(1,length(X2)) </i></b></span></div><div style="mso-line-spacing: &quot;80 20 0&quot;; mso-margin-left-alt: 216; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span lang="EN-US" style="COLOR: #006600; mso-fareast-font-family: 宋体; mso-hansi-font-family: Arial; mso-fareast-language: ZH-CN;"><b><i>plot(X2,Y2,’o’)</i></b></span><span lang="EN-US" style="COLOR: #006600; FONT-FAMILY: 宋体; mso-fareast-font-family: 宋体; mso-hansi-font-family: Arial; mso-fareast-language: ZH-CN;"><b>
3 |1 y5 O3 u( s) l$ a                                </b></span></div><div style="mso-line-spacing: &quot;80 20 0&quot;; mso-margin-left-alt: 216; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span lang="EN-US" style="COLOR: #006600; mso-fareast-font-family: 宋体; mso-hansi-font-family: Arial; mso-fareast-language: ZH-CN;"><b>2) </b></span><span style="COLOR: #006600; FONT-FAMILY: 宋体; mso-fareast-font-family: 宋体; mso-hansi-font-family: Arial;"><b>网络结构：输入：</b></span><span lang="EN-US" style="COLOR: #006600; mso-fareast-font-family: 宋体; mso-hansi-font-family: Arial; mso-fareast-language: ZH-CN;"><b>1; </b></span><span style="COLOR: #006600; FONT-FAMILY: 宋体; mso-fareast-font-family: 宋体; mso-hansi-font-family: Arial;"><b>隐含：</b></span><span lang="EN-US" style="COLOR: #006600; mso-fareast-font-family: 宋体; mso-hansi-font-family: Arial; mso-fareast-language: ZH-CN;"><b>7 tanh</b></span><span style="COLOR: #006600; FONT-FAMILY: 宋体; mso-fareast-font-family: 宋体; mso-hansi-font-family: Arial;"><b>元</b></span><span lang="EN-US" style="COLOR: #006600; mso-fareast-font-family: 宋体; mso-hansi-font-family: Arial; mso-fareast-language: ZH-CN;"><b>; </b></span><span style="COLOR: #006600; FONT-FAMILY: 宋体; mso-fareast-font-family: 宋体; mso-hansi-font-family: Arial;"><b>输出</b></span><span style="COLOR: #006600; mso-fareast-font-family: 宋体; mso-hansi-font-family: Arial;"><b> 1 </b></span><span style="COLOR: #006600; FONT-FAMILY: 宋体; mso-fareast-font-family: 宋体; mso-hansi-font-family: Arial;"><b>线性元 </b></span></div><div style="mso-line-spacing: &quot;80 20 0&quot;; mso-margin-left-alt: 216; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span style="COLOR: #006600; FONT-FAMILY: 宋体; mso-fareast-font-family: 宋体; mso-hansi-font-family: Arial;"><b>训练算法</b></span><span lang="EN-US" style="COLOR: #006600; mso-fareast-font-family: 宋体; mso-hansi-font-family: Arial; mso-fareast-language: ZH-CN;"><b>: BP</b></span><span style="COLOR: #006600; FONT-FAMILY: 宋体; mso-fareast-font-family: 宋体; mso-hansi-font-family: Arial;"><b>算法</b></span><span lang="EN-US" style="COLOR: #006600; mso-fareast-font-family: 宋体; mso-hansi-font-family: Arial; mso-fareast-language: ZH-CN;"><b>, Levenberg-Marquardt</b></span><span style="COLOR: #006600; FONT-FAMILY: 宋体; mso-fareast-font-family: 宋体; mso-hansi-font-family: Arial;"><b>算法 </b></span></div><div style="mso-line-spacing: &quot;80 20 0&quot;; mso-margin-left-alt: 216; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span lang="EN-US" style="COLOR: #006600; mso-fareast-font-family: 宋体; mso-hansi-font-family: Arial; mso-fareast-language: ZH-CN;"><b>3) </b></span><span style="COLOR: #006600; FONT-FAMILY: 宋体; mso-fareast-font-family: 宋体; mso-hansi-font-family: Arial;"><b>要求： </b></span></div><div style="mso-line-spacing: &quot;80 20 0&quot;; mso-margin-left-alt: 216; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span lang="EN-US" style="COLOR: #006600; mso-fareast-font-family: 宋体; mso-hansi-font-family: Arial; mso-fareast-language: ZH-CN;"><b>a) </b></span><span style="COLOR: #006600; FONT-FAMILY: 宋体; mso-fareast-font-family: 宋体; mso-hansi-font-family: Arial;"><b>比较一般</b></span><span lang="EN-US" style="COLOR: #006600; mso-fareast-font-family: 宋体; mso-hansi-font-family: Arial; mso-fareast-language: ZH-CN;"><b>BP</b></span><span style="COLOR: #006600; FONT-FAMILY: 宋体; mso-fareast-font-family: 宋体; mso-hansi-font-family: Arial;"><b>算法（</b></span><span lang="EN-US" style="COLOR: #006600; mso-fareast-font-family: 宋体; mso-hansi-font-family: Arial; mso-fareast-language: ZH-CN;"><b>trainbp</b></span><span style="COLOR: #006600; FONT-FAMILY: 宋体; mso-fareast-font-family: 宋体; mso-hansi-font-family: Arial;"><b>）</b></span><span lang="EN-US" style="COLOR: #006600; mso-fareast-font-family: 宋体; mso-hansi-font-family: Arial; mso-fareast-language: ZH-CN;"><b>,</b></span><span style="COLOR: #006600; FONT-FAMILY: 宋体; mso-fareast-font-family: 宋体; mso-hansi-font-family: Arial;"><b>弹性</b></span><span lang="EN-US" style="COLOR: #006600; mso-fareast-font-family: 宋体; mso-hansi-font-family: Arial; mso-fareast-language: ZH-CN;"><b>BP</b></span><span style="COLOR: #006600; FONT-FAMILY: 宋体; mso-fareast-font-family: 宋体; mso-hansi-font-family: Arial;"><b>算法</b></span><span lang="EN-US" style="COLOR: #006600; mso-fareast-font-family: 宋体; mso-hansi-font-family: Arial; mso-fareast-language: ZH-CN;"><b>(trainrp), Levenberg-Marquardt(trainlm)</b></span><span style="COLOR: #006600; FONT-FAMILY: 宋体; mso-fareast-font-family: 宋体; mso-hansi-font-family: Arial;"><b>算法的收敛时间和精度，给出每一次迭代后的性能指标； </b></span></div><div style="mso-line-spacing: &quot;80 20 0&quot;; mso-margin-left-alt: 216; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span lang="EN-US" style="COLOR: #006600; mso-fareast-font-family: 宋体; mso-hansi-font-family: Arial; mso-fareast-language: ZH-CN;"><b>b) </b></span><span style="COLOR: #006600; FONT-FAMILY: 宋体; mso-fareast-font-family: 宋体; mso-hansi-font-family: Arial;"><b>测试以上模型的精度。 </b></span></div><div style="mso-line-spacing: &quot;80 20 0&quot;; mso-margin-left-alt: 216; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"><span lang="EN-US" style="COLOR: #006600; mso-fareast-font-family: 宋体; mso-hansi-font-family: Arial; mso-fareast-language: ZH-CN;"><b>c) </b></span><span style="COLOR: #006600; FONT-FAMILY: 宋体; mso-fareast-font-family: 宋体; mso-hansi-font-family: Arial;"><b>比较</b></span><span lang="EN-US" style="COLOR: #006600; mso-fareast-font-family: 宋体; mso-hansi-font-family: Arial; mso-fareast-language: ZH-CN;"><b>20</b></span><span style="COLOR: #006600; FONT-FAMILY: 宋体; mso-fareast-font-family: 宋体; mso-hansi-font-family: Arial;"><b>个隐含元的神经网络建模精度，初始权值的影响，得出你的结论。 </b></span></div><div style="mso-line-spacing: &quot;80 50 0&quot;; mso-margin-left-alt: 216; mso-char-wrap: 1; mso-kinsoku-overflow: 1;"></div></div>

小溪的空气

很急，希望高手们能够指教。。