function [y1]=neural_k(p)
k1=1;
k2=2;
k3=4;
k4=8;
n=5;
t1=1+sin(k1*pi/4*p);
t2=1+sin(k2*pi/4*p);
t3=1+sin(k3*pi/4*p);
t4=1+sin(k4*pi/4*p);
net=newff(minmax(p),[n,1],{'tansig','purelin'},'trainlm');
net.trainParam.epochs=100;
net.trainParam.goal=0.0001;
net.trainParam.show=100;
net=train(net,p,t1);
net1=train(net,p,t2);
net2=train(net,p,t3);
net3=train(net,p,t4);
figure;
y1=sim(net,p);
y2=sim(net1,p);
y3=sim(net2,p);
y4=sim(net3,p);
subplot(2,2,1)
plot(p,y1,':',p,t1,'-')
legend('\fontsize{6}\bf训练后输出','\fontsize{6}\bf目标输出')
xlabel('\fontsize{9}\bfp (k=1)')
ylabel('\fontsize{9}\bf输出a/t')
subplot(2,2,2)
plot(p,y2,':',p,t2,'-')
legend('\fontsize{6}\bf训练后输出','\fontsize{6}\bf目标输出')
xlabel('\fontsize{9}\bfp (k=2)')
ylabel('\fontsize{9}\bf输出a/t')
subplot(2,2,3)
plot(p,y3,':',p,t3,'-')
legend('\fontsize{6}\bf训练后输出','\fontsize{6}\bf目标输出')
xlabel('\fontsize{9}\bfp (k=4)')
ylabel('\fontsize{9}\bf输出a/t')
subplot(2,2,4)
plot(p,y4,':',p,t4,'-')
legend('\fontsize{6}\bf训练后输出','\fontsize{6}\bf目标输出')
xlabel('\fontsize{9}\bfp (k=8)')
ylabel('\fontsize{9}\bf输出a/t')