
Ublas : 
From: Neal Becker (ndbecker2_at_[hidden])
Date: 20071210 10:37:01
Sebastian Gesemann wrote:
> On Dec 10, 2007 4:07 PM, Neal Becker <ndbecker2_at_[hidden]> wrote:
>
>> So, we actually _want_ iterators of a zero vector to skip over the zeros?
>> I
>> guess I really don't understand this.
>>
>
> The thing is that a zero vector doesn't actually store the zeros. So,
> there's nothing to iterate over. Same thing with sparse vectors and
> matrices. Skipping (unstored) zeros is a good thing during calculations
> (i.e. a dot product) to speed things up, I guess.
>
> Cheers!
> SG
I understand that it doesn't store the zeros  that's why I used it. I
thought it was supposed to act _as if_ it had stored the zeros.