MATLAB MatLab Matrix Help: Integrating for Entries Equal to 1

[Apteronotus]

Hi,

I have a quick question regarding MatLab.

I have 3 matracies A, B and C.

For every entry equal to 1 in B, I want to let the corresponding entry in A be an integral of x from 0 to C.

ex.
for all (i,j)
if B(i,j)==1 then let A(i,j)=quad(@(x) x, 0, C(i,j))

A quick way to do this for large matracies I thought was to use the following syntax:
A(B==1) = quad(@(x) x, 0, C(B==1))

But get the following error:
? Error using ==> quad at 70
The limits of integration must be scalars.

Is there any way around this other than a "for i, for j" statement?

Thanks,

 

[Wrichik Basu]

First, don't use quad function; Matlab no longer recommends it. Instead, use the integral function:
https://in.mathworks.com/help/matlab/ref/integral.html

Is there any way around this other than a "for i, for j" statement?

I don't think so.

 

[RPinPA]

I haven't tried it, but ARRAYFUN may be what OP is looking for.

https://www.mathworks.com/help/matlab/ref/arrayfun.html
But just a general comment, don't assume a function is automatically vectorized unless the documentation explicitly says it is.