Question

I’m trying to plotting a function but I receive an error and since I’m a newbie I don’t know how to fix it.

 f=-10:0.001:10;
 >> w=1/sqrt(4+(2*pi*f)^2);
 ??? Error using ==> mpower
 Inputs must be a scalar and a square matrix.
 To compute elementwise POWER, use POWER (.^) instead.

where is the mistake?

Answer 1

^ is the matrix power operator, mpower. The syntax A^n attempts to raise the (square) matrix A to the nth power. This will obviously fail if A is not a square matrix (in your example, it is a vector).

Since your username includes eng and you’re posting about MATLAB, I assume that you are an engineering student – your introductory math course should have covered matrix math, and why A * A is only defined for square A.

You actually want the scalar operator .^, as in A.^n. This raises each element of A to the nth power.