p=[724.570000000000,739.774223126620,771.489090673942,804.563606600594,839.056060404793,875.027240514377,912.540541418428,951.662075391767,992.460789009143,1035.00858465455]) v5 a% V h! O4 @$ R
t=[724.570000000000,746.620000000000,778.270000000000,800.800000000000,827.750000000000,871.100000000000,912.370000000000,954.280000000000,995.010000000000,1037.20000000000] - e# W( u# G, v: ?. ^7 b [pn,minp,maxp,tn,mint,maxt]=premnmx(p,t); %原始数据归一化) V, p. e4 D$ i
: I8 i0 f3 E5 r" ?* Enet=newff(minmax(pn),[9,1],{'tansig','purelin'},'traingdx'); %设置网络,建立相应的BP网络; m3 s4 P+ y; |/ c+ D
net.trainParam.show=2000; % 训练网络 + L1 D8 Z3 G2 V1 S" P. n+ @net.trainParam.lr=0.01; / e; U# t! _8 q9 I% ^9 T4 anet.trainParam.epochs=10000;6 F3 R( U: {5 w8 u7 D
net.trainParam.goal=1e-5; $ u% C! f7 F j" @8 }8 A) U[net,tr]=train(net ,pn,tn); %调用TRAINGDM算法训练BP网络 2 |! G, {$ }2 p, {8 b/ x3 _& R+ g7 U7 B: M2 p
an=sim(net,pn); %对BP网络进行仿真9 J& E# a A# D( ]4 q2 m' s
a=postmnmx(an,mint,maxt); %还原数据 - O0 x! B: _" b* |x=2001:2010; S; `9 o, J& H9 Z
newk=a(1,;+ |" z( |8 W+ z6 n# Q
plot(x,newk,'r-o',x,t,'b--+') . M: \1 w4 r9 q1 alegend('网络输出值/万人','实际人口数/万人');6 P3 `/ M5 r, @) ]6 C$ H. N
xlabel('年份'); 4 p8 w! i1 D1 p' O) b8 mylabel('人口数');6 A& c! E5 }; q3 @# I
title('预测人口数对比表'); {( B1 Y. c1 K/ f. h: V
2 v' V+ w- x2 ~, Ypnew1=[1079.38044723977,1125.65457635540,1173.91252408743,1224.23933874207,1276.72371473226,1331.45814888992,1388.53910347951,1448.06717620014,1510.14727747579,1574.88881534617]- q( _4 [2 d* v3 O
pnew=pnew1 ' K& O3 {' Z" R5 ipnewn=tramnmx(pnew,minp,maxp); & [ U) g6 s/ @, sanewn=sim(net,pnewn); %对BP网络进行仿真 0 K D3 b5 B- S$ H5 zanew=postmnmx(anewn,mint,maxt); %还原数据. R# r1 x% e& x2 U3 ^3 M
y=anew'6 d. K# y, b, j3 s
- o9 l3 @) r) W3 Q3 f3 E9 s/ E : Y, V( @* k* f. u预测的结果怎么都一样呀?》??求助