Question

I have these 2 vectors:

alpha =      1    1    1    1    1    1    1    1    1  f_uv =    193  193  194  192  193  193  190  189  191 

And when I do this:

alphaf_uv = alpha * f_uv' 

I get the error message:

'??? Error using ==> mtimes Integers can only be combined with integers of the same class, or scalar doubles.'  

The interesting part is that this error doesn’t appear if I define the same vectors in the console and try the multiplication there.

alpha is defined by me and f_uv is obtained from some pixels in a PNG image.

Answer 1

Assuming they’re both integer matrices to begin with, f_uv' may not be.

Try:

alphaf_uv = double(alpha) * double(f_uv') 

and let us know if it still occurs.

You may need to turn alphaf_uv back into an integer type afterwards, depending on your needs.