Re: copy values from

Gerhard Wolf wrote:
> Hi,
> 
> i have to vectors.
> std::vector<double> a;
> std::vector<double> b;
> same type, size and have synchronous value pairs. The values in "a" are 
> decimal time values (linear increasing).

You mean they are sorted? If they aren't create a couple of working 
copies and sort them.

Now look up std::merge. Note that all sequence algorithms work correctly 
as long as you can provide start and one past the end iterators for the 
sequence. In this case you need the iterator for the first element of 
the (sorted) a and b  that is greater than the startvalue and the the 
iterators for the first element in each that is greater than the 
endvalue. Also note that you will need to know how many elements there 
will eventually be in the merged result.

> 
> Now i want to copy in a 3rd vector "c" all elements from a start value 
> to a end value. My first idea was something like:
> 
> std::vector<double> c;  // target
> for (std::vector<double>::iterator it=a.begin(); it != a.end(); it++) {
>   if (*it > startvalue && *it < endvalue) {
>     c.push_back(?);   
>  }
> }
> 
> do i need a 2nd iterator for vector b !? but how?
> or ist there a easier was to get the values to vector c?