数学建模社区-数学中国
标题:
求助
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作者:
422258511
时间:
2012-6-19 20:47
标题:
求助
p=[724.570000000000,739.774223126620,771.489090673942,804.563606600594,839.056060404793,875.027240514377,912.540541418428,951.662075391767,992.460789009143,1035.00858465455]
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t=[724.570000000000,746.620000000000,778.270000000000,800.800000000000,827.750000000000,871.100000000000,912.370000000000,954.280000000000,995.010000000000,1037.20000000000]
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[pn,minp,maxp,tn,mint,maxt]=premnmx(p,t); %原始数据归一化
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net=newff(minmax(pn),[9,1],{'tansig','purelin'},'traingdx'); %设置网络,建立相应的BP网络
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net.trainParam.show=2000; % 训练网络
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net.trainParam.lr=0.01;
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net.trainParam.epochs=10000;
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net.trainParam.goal=1e-5;
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[net,tr]=train(net ,pn,tn); %调用TRAINGDM算法训练BP网络
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an=sim(net,pn); %对BP网络进行仿真
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a=postmnmx(an,mint,maxt); %还原数据
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x=2001:2010;
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newk=a(1,
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plot(x,newk,'r-o',x,t,'b--+')
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legend('网络输出值/万人','实际人口数/万人');
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xlabel('年份');
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ylabel('人口数');
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title('预测人口数对比表');
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pnew1=[1079.38044723977,1125.65457635540,1173.91252408743,1224.23933874207,1276.72371473226,1331.45814888992,1388.53910347951,1448.06717620014,1510.14727747579,1574.88881534617]
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pnew=pnew1
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pnewn=tramnmx(pnew,minp,maxp);
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anewn=sim(net,pnewn); %对BP网络进行仿真
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anew=postmnmx(anewn,mint,maxt); %还原数据
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y=anew'
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预测的结果怎么都一样呀？》？？求助
作者:
wssl103050
时间:
2012-6-19 22:57
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