Error in Integration of Cell Array

Hello,

I am trying to perform integration on a cell array using the following code:

r = 2;
phi_e = 1.3694;
for e =1:1:size(A_schnitt,1)
    for y =1:1:size(A_schnitt{e,1},1)
        for u =1:1:size(A_schnitt{e,1},2)
            fun= @(thetha_P) ((1/(2*pi))*A_schnitt{e,1}{y,u}.*exp(-1i*r*thetha_P(y,u)));
            A{e,y,u}= integral(fun,0,phi_e, 'ArrayValued',true)
            
        end
    end
end

I am attaching the files

A_schnitt a multipel cell array which contains (5x1 cells, then each cell contains 3x63 cells and each cell is than a 2x2 matrix) and thetha_P which is a 3x63 double array.

The error which I am getting is

Index in position 2 exceeds array bounds (must not exceed 1).

Error in integralCalc/iterateArrayValued (line 156)

Error in integralCalc/iterateArrayValued (line 156)

fxj = FUN(t(1)).*w(1);

Error in integralCalc/vadapt (line 130)

[q,errbnd] = iterateArrayValued(u,tinterval,pathlen);

Error in integralCalc (line 75)

[q,errbnd] = vadapt(@AtoBInvTransform,interval);

Error in integral (line 88)

Q = integralCalc(fun,a,b,opstruct);

Does anyone knows..?

Answer 1

[Walter Roberson]

fun= @(thetha_P) ((1/(2*pi))*A_schnitt{e,1}{y,u}.*exp(-1i*r*thetha_P(y,u)));
A{e,y,u}= integral(fun,0,phi_e, 'ArrayValued',true)

integral() is going to call the given function. Normally it would pass in a vector of values, but because you indicated ArrayValued as true, integral() is going to pass in one value at a time.

Inside your anonymous function, that scalar value is going to be received as the variable thetha_P . As indicated, it will be a scalar. But you attempt to index it with thetha_P(y,u)

thetha_P which is a 3x63 double array.

Not inside that anonymous function it will not be. You said @(thetha_P) so inside the anonymous function thetha_P is what is passed in, not whatever value thetha_P might have in the workspace.

I have to ask what variable you are integrating with respect to? What value in fun is intended to range over 0 to phi_e with the integral being formed out of it?

[Chris Dan]

Walter Roberson

I am integrating with respect to the variable thetha_P. It has to be limited by phi_e and zero.

Here is the picture, which I am trying to do

here a(phi) is the matrix which is 2x2 and phi on the exponential is thetha_P. so I am trying to integrate a matrix

[Walter Roberson]

What is the role of your thetha_P matrix in this? Why are you indexing it in your code?

[Chris Dan]

I got it actually, I had to use another variable for integration apart from thetha_P, then it works