Re: [boost] [svg_plot] Progress of SVG_Plot

From: Lewis Hyatt (lhyatt_at_[hidden])
Date: 2007-07-31 12:05:19

> This is what I meant when I said that I was having problems. It
> currently accepts maps, and I didn't change the language in the
> documentation clear enough. My view on the 1D containers (vector, etc)
> is that a user will have a single container, and want to plot it in
> two dimensions, with the index of the data being the X coordinate, and
> the value stored being the Y value, and the behavior will be changed
> to reflect that. I will look into your suggestions and see how that
> affects my program. I'm a little fuzzy on C++ concepts, and I didn't
> see a way to say that the containers hold pair<,>s.

OK, well I think what you want to do is set up the interface so that, 
instead of expecting a container which provides begin() and end(), you 
expect anything conforming to Boost.Range. (This should not be a major 
change, just some minor syntax adjustments). The other use cases, such 
as passing in a separate vector<> for x and y, or passing in only y and 
having x be auto-generated, are easily adapted to this interface using 
boost::zip_iterator and boost::counting_iterator. You might choose to 
support that directly by providing alternate overloads which do the 
adaptation for the user. I think what seems most natural to me is that 
you can provide two overloads of plot(x), where x can be:

-a Boost.Range with a value_type of std::pair<T,U> (what you have now)
-a Boost.Range with a value_type of T, in which case you will provide an 
adaptor which auto-generates the x axis from the data indices

Additionally, there could be another overload accepting two ranges, 
plot(x,y), where x and y are each a Boost.Range with value_type T.

Basically, since you've already implemented the first interface, you 
could quickly support the other two just by using the boost iterator 
adaptors zip_iterator and counting_iterator.

-Lewis