NS L8

clear;
x = [0:0.05:1];
a = 0.1;
b = 0.36;
c = 0.81;
d = 0.15;
y = a.*x.^3 + b.*x.^2 + c.*x + d

for i = 1:100
     a = rand;
     b = rand;
     c = rand;
     d = rand;
     T(1,i) = a;
     T(2,i) = b;
     T(3,i) = c;
     T(4,i) = d;
     P(i,:)=a.*x.^3 + b.*x.^2 + c.*x + d;
end;
P=P';
net =newff(minmax(P),[7 4], { 'tansig', 'purelin'},'trainlm');
net.trainParam.epochs = 500;
[net] = train(net,P,T);
K = sim(net,y')

a = 0.9;
b = 0.81;
c = 0.87;
d = 0.005;

y1 = a.*x.^3 + b.*x.^2 + c.*x + d;
K = sim(net,y1')