Calculating gradient of a matrix - too many outputs... Not sure why?

Hello,

I have calculated a result matrix using the integrating function on matlab, however when I try to calculate the gradient of the result matrix, it says I have too many outputs.

My code is as follows:

x = linspace(-1,1,40);
y = linspace(-2,2,40);

for ii = 1:numel(x);

    for jj = 1:numel(y)

        fun = @(x) x(ii) + y(jj)

     V(ii,jj) = integral(fun, 0, 2()); 
end
end

[qx,qy] = -gradient(V);

I tried to set up a meshgrid first to do my calculation over x and y, however the integral matlab function couldn't handle a meshgrid.

Any idea how I could calculate the gradient of my resulting V function?

Note that I have replaced my actual function with a more simple function. I could not calculate the integral of my function directly and thus am resorting to numerical integration.

[Stephen23]

Please show the complete error message. This means all of the red text.

[Mark Lepage]

Hey Stephen, my apologies, I had an error in my above code (I have fixed it)

But here is the complete error message:

>> [qx,qy] = -gradient(V);
Error using  - 
Too many output arguments.

Answer 1

[Mark Lepage]

I can't believe I didn't notice this,

But the error stems from the negative sign I had in front of the gradient function.

I removed this, and everything works great.

x = linspace(-1,1,40);
y = linspace(-2,2,40);
for ii = 1:numel(x);
    for jj = 1:numel(y)
        fun = @(x) x(ii) + y(jj)
     V(ii,jj) = integral(fun, 0, 2()); 
end
end
[qx,qy] = gradient(V);