How do I vectorize a sum involving an anonymous function?

Hi

I have a sum that involves an anonymous function g of the form

beam = sum_{k=-K}^{k=K} A(k) g(x-c(k))

where A and c are know vectors of length n. I would like to be able to pass beam a vector x of length m ~= n AND vectorize the result. I have tried arrayfun, but get dimension mismatches. Is there any way to implement this without resorting to a loop?

Thank you

Norm

Answer 1

[Iain]

Tricks to try: bsxfun, summation along the right column/row, replicating matrices as needed (repmat)

Answer 2

[Michael Haderlein]

So you have a matrix g, right? Then, you don't need to sum by hand but just multiply g*A. Such as

>> x=(1:4)';
>> k=0:5;
>> A=k'.^2;
>> g=x*sqrt(k);
>> g*A

ans =

    110.1470
    220.2940
    330.4410
    440.5880

In this example, the first value 110 is g(x(1),k)*A(k) and so on:

>> sum(g(1,:).*A')

ans =

    110.1470