Suppose I have a high dimensional vector v which is dense and another high dimensional vector x which is sparse and I want to do an operation which looks like
v = v + x
Ideally since one needs to update only a few entries in v this operation should be fast but it is still taking a good amount of time even when I have declared x to be sparse. I have tried with v being in full as well as v being in sparse form and both are fairly slow.
I have also tried to extract the indices from the sparse vector x by calling a find and then updating the original vector in a for loop. This is faster than the above operations, but is there a way to achieve the same with much less code.
Thanks