How to make Subscript indices real positive integers or logicals?

I wrote this code in order to create a neural network to approach the function f(x,y,z)=z^2 + x^3 -2xcos(yz+4) within [-1,1].

clc; clear;
x = -1:.01:1;
y = -1:.01:1;
z = -1:.01:1;
f=z.*z + x.*x.*x -2*x.*cos(y.*z +4); 
            
Px=x; Py=y; Pz=z; P={Px;Py;Pz}; T=f; 


net=newff([-1 1], [30,30,1], {'tansig','tansig','purelin'},'traingd'); 

net.trainParam.show = 200; 
net.trainParam.lr = 0.01;  
net.trainParam.epochs =5000;
net.trainParam.goal = 1e-5;
net.numinputs = 3;
  
trained = train(net,P, T); 


N = 100;
Pxtest = 4*rand(1,N);
Pytest = 4*rand(1,N);
Pztest = 4*rand(1,N);
Ptest=[Pxtest;Pytest;Pztest];
fTest = f(Ptest);

testing= sim(trained,Ptest);


plot(Ptest,atest,'ro', Ptest,fTest,'b*'); grid;
legend('predicted value','actual value')

When I run it, I get the Error :

Subscript indices must either be real positive integers or logicals.

Error in approach_function(line 26)

fTest = f(Ptest);

How can I make that right?

[Rik]

Don't edit away relevant parts of your question. I restored it from the Google cache and made a capture of this page on the Wayback Machine.

[Rik]

Why do you want to edit away parts of your question? If you explain why you want to do that, you might convince me to stop reverting your edits. Otherwise this will turn into a test of who is more stubborn.

[Nick]

i want to delete the question

[Rik]

Why do you want to delete the question? If you want private help you should hire a consultant instead of posting on a public forum.

Just so others can still read it after you attempt to delete it:

I wrote this code in order to create a neural network to approach the function f(x,y,z)=z^2 + x^3 -2xcos(yz+4) within [-1,1].

clc; clear;
x = -1:.01:1;
y = -1:.01:1;
z = -1:.01:1;
f=z.*z + x.*x.*x -2*x.*cos(y.*z +4); 
            
Px=x; Py=y; Pz=z; P={Px;Py;Pz}; T=f; 


net=newff([-1 1], [30,30,1], {'tansig','tansig','purelin'},'traingd'); 

net.trainParam.show = 50; 
net.trainParam.lr = 0.01;  
net.trainParam.epochs =1000;
net.trainParam.goal = 1e-5;
net.numinputs = 3;
%Train  
net1 = train(net,P, T); 


N = 100;
Pxtest = 4*rand(1,N);
Pytest = 4*rand(1,N);
Pztest = 4*rand(1,N);
Ptest=[Pxtest;Pytest;Pztest];
fTest = f(Ptest);

atest= sim(net1,Ptest);

mse = sum((fTest-atest).^2)/N;
fprintf('Mean square Error = %.4f\n', mse)
% Plot 
plot(P,T,'r--',Ptest,atest,'ro', Ptest,fTest,'b*'); grid;
legend('Function','predicted value','actual value')

When I run it, I get the Error :

Subscript indices must either be real positive integers or logicals.

Error in approach_function(line 26)

fTest = f(Ptest);

How can I make that right?

[Rik]

Why do you want to delete the question?

Answer 1

[Image Analyst]

A thourough explanation of the error is in the FAQ:

https://matlab.fandom.com/wiki/FAQ#.22Subscript_indices_must_either_be_real_positive_integers_or_logicals..22