MATLAB: A way to short-circuit “any”

Question

Hello,

My code is bottlenecked by many calls of the following line:

if any(vectorA & vectorB)

where vectorA and vectorB are large, sparse, and logical.

Specifically, these vectors are 1.4M elements long and average 0.6% non-zeros. However, due to the previous calculations, they share a common non-zero quite often (say roughly half the time). As written, the & operation is performed before the any.

Since this is the natural bottleneck, I've been looking for ways to improve the computation, and short circuiting out comes to mind, but I haven't found an elegant way to do this in Matlab.

Does anyone know a slick optimization?

Thanks!

-Kyle

Answer 1

Is the multiplication faster?

if any(vectorA .* vectorB)

But I do not assume that this helps, because you still process more elements than needed. You need a Mex function for short-cutting. For full arrays you find in the FEX: anyExceed and anyEq. But substantial modifications are required for accessing sparse arrays.