How can I solve this MATLAB “Matrix dimensions must agree” error?

Question

I am typing some code for a class but every time I run the function I get the same error:

??? Error using ==> plus
Matrix dimensions must agree.

Error in ==&         


        

Answer 1

How do you expect -x2.^2-y1.^2 to work when x2 and y1 is of different size? x2=0:0.1:5 has fifty or so entires while y1=-5:0.1:5 has a hundred or so entries.