Re: [PyX-devel] Re: [PyX-user] bar chart x-axis custom labels

[Andre W. <wo...@us...>]

Hi Pieter,

On 10.02.05, pieter claassen wrote:
> Last few questions regarding clean-up and axis:
> 
> 1. Is getting the path cleaned-up as simple as adding the appropriate
> start and finishing points to not start in thin air?

In practice yes. I think the suggested style will work for you at the
moment quite well. But its not a solution to be added to the PyX core.
I'll give you some hints, why I think so.

> 2. I haven't check the axis, but will the parter do the right thing with
> labels if I add large numbers of data points? (I am at work otherwise I
> would have checked this myself;-)

Sure, the parter will do (mostly), what you want. If it doesn't, you
could use the handy "density" parameter of the axis, or, when you want
more control, put your own parter in (for example a manual parter). Or
place some manual marks yourself. Since you have a standard linear (or
logarithmic) axis now, you can do all these "standard" things ...

> 3. Anything else that you think needs to be cleaned up?

Just some ideas, which to my mind need to be addressed:

- Make the graph dimensions interchangeable.
- Add the baseline of the histogram (like fromvalue in barpos).
- Add some kind of variable width handling. In the first this will
  lead to some more verbose data need to be passed into the style. I
  would start in using the pos and range style. Just like an errorbar.
  Starting from that we could add some histogram data creation, which
  could (a) calculate the width or (b) make some educated guess for
  the widths out of the data it gets.
- Proper handling of "out of graph" parts (i.e. skip them). Do not use
  clipping for that.
- Some graphical enhancements: A switch to make the histogram
  step-like (as in gnuplot) or barlike (with lines down to the
  baseline as we have it now). And the output path should be improved
  (be sophisticated and use as less path items as possible).

That would be cool.


André

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