Alex wrote:
> Th only problem is that I am going to need to create different dataset and
> graph them on the fly. Writing files out and then shelling doesn't quite
> sound like the most efficient way of doing things. Or am I missing things?
>
> Basically I will have a HUGE collection of data to pull from, then viewers
> will select what of that data they want plotted. Then my app should plot
> it.
> Make sense?
>
> It's seeming kind of like I will need to try a few of these to see what will
> work.
> Do you all agree that starting with GD::Graph is probably the best way to
> start?
I used GD::Graph for a project I did about a week ago. I've used it before,
but this was the first time someone cared about how 'pretty' the output was,
as opposed to simply how functional it was. My data consisted of an arbitrary
number of items graphed along time (x) as a bar or a line.
I found that if you are willing to spend a lot of time mucking around with
the colours, and you can take steps to crop your data if it will make the
graph too crowded, the results are not too bad. They are not beautifully
polished, but they are presentable.
Two problems in particular that I noted were that the legend sometimes
obscures data on the right, and sometimes the calculations for the steps/height
of the y-axis are just wacky (for example: steps of .25 when dealing with
only whole numbers, or a top height of 2x the highest y-value). I recommend
making your own calculations concerning Y and forcing GD::Graph to play along.
Also if you have many different items, you may want to cluster them around
your points at the X-axis for clarity by introducing an ignored element.
This makes it much easier to see what is going on if you have (for instance)
5 elements being displayed at each point of x.
- Ann
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