Re: Is there an STL algo to fill a vector with product of 2 other vectors?

From:

James Kanze <james.kanze@gmail.com>

Newsgroups:

comp.lang.c++

Date:

Tue, 9 Dec 2008 09:09:38 -0800 (PST)

Message-ID:

<8807236d-e982-47cd-ad78-8c68507e36b4@o4g2000pra.googlegroups.com>

On Dec 9, 3:43 pm, Steve555 <foursh...@btinternet.com> wrote:

I'm looking for an algorithm that takes 2 vectors and a
function pointer as arguments? I want to use the function
pointer to calculate a result e.g. the product, and put the
result either in place, or in a third vector.

I've looked through the list of algorithms and there doesn't
appear to be one. transform() is the closest, but alas works
on only a single vector.

There are two versions of std::transform. The following code
should do the trick:
    assert( v1.size() == v2.size() ) ;
    std::transform( v1.begin(), v1.end(),
                    v2.begin(),
                    std::back_inserter( v3 ),
                    std::multiplies< double >() ) ;

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