que1shenjing.m

signal and system answer

clear
t=[17.2826037793333,20.667320304245386,22.1261988867878,23.75152470345166,26.24278611857329,26.181763109257727,27.388991079689315,28.628890637533704,29.989166388864476,31.100163888115553,31.439546959691384,32.267552167555415,33.10681891914629,33.76225482136267,34.453850068664046,34.97857341827298,35.57753458386883,36.00561606715445,36.38266565030136,36.689552388996596,36.916187077723926,37.06386312324576,37.40493975169222,36.603588300033344,36.27122879033303,36.62423479392964,37.10925354983659,37.23018189152908,37.39688760368233,37.52192597386059,37.45905234181411,37.63463605649411,37.60996124205325,37.83242862638944,37.97921214216001,37.862832173336606,37.80618377472244,37.08768586438699,37.07700393937369,35.084187650540365];
p=1:40;
p=p+1;
n=20;
net=newff([0,100],[n 1],{'tansig' 'purelin'},'trainlm');
net.trainParam.epochs=2000;
net.trainParam.lr=0.05;
net.trainParam.goal=0.1;
[net,tr]=train(net,p,t); 
y=sim(net,p);
figure
pk=41:60;
y1=sim(net,pk);
plot(p,t,'b')
hold on
plot(pk,y1,'g')