ticks of axis about owl HOT 8 CLOSED

This is possible in PLplot using either Plplot.Plot.axes or Plplot.plslabelfunc. Owl may need some modification to integrate this properly but the underlying support is there.

from owl.

Thanks ! Indeed the underlying structure is abstract in Owl :-/

from owl.

@zoggy Definitely an important function, I added it. I hope the following code will work for you for the time being. It is only in the master branch and not in the OPAM release yet.

let x = Vec.sequential 4;;
let y = Vec.uniform 4;;
let h = Plot.create "labeltest.pdf";;
Plot.plot ~h x y;;
Plot.set_xticklabels h [0.,"Jan"; 1.,"Feb"; 2.,"Mar"; 3.,"Apr"];;
Plot.output h;;

from owl.

Plot module is actually quite straightforward. All the information of a page is saved in a record (of type page). All the operations you have done on a page will be cached in a list page.plots. Whenever you call output function, Plot module will call _initialise, _prepare_page, _finalise these three functions to actually finish "drawing" your plot then output.

from owl.

Thanks. I had to opam pin to master branch of eigen too but no problem.

Plot.set_xticklabels works, except that some labels do not appear; I though this was a question of missing space and reduced the font size, but no. Is there something more to do ?

from owl.

I guess this is because currently Owl only draws at the major ticks, the reason is plslabelfunc calls the callback function whenever it encounters the major ticks. @hcarty should know more about how to customise the ticks in Plplot.

from owl.

First an API suggestion: maybe the Plot.set_*ticklabels function should take a list of (value : float, label : string) tuples? That will guarantee that a user can't accidentally pass in lists of mismatched lengths.

Second, regarding tick spacing and labeling - there is detection logic in the C core of PLplot which handles this. I don't recall the details - it's been a while since I hacked on that code - but it is possible to manually specify the major (plsmaj) and minor (plsmin) tick spacing. IIRC all major ticks are labeled by default.

For for your months example @zoggy, if no sub-monthly variability is shown, the major tick spacing would be 1.0 and minor ticks would be hidden.

from owl.

The API suggestion is really nice. I have changed it.

from owl.