Re: desired features for gp backend?

[Ben Abbott]

On Friday, June 19, 2009, at 11:59AM, "Rob Mahurin" <address@hidden> wrote:
>On Jun 18, 2009, at 6:35 PM, Ben Abbott wrote:
>> Regarding the old thread, I noticed the suggestion to allow the  
>> ticklabels to be formated as ...
>>
>>      set (gca, "xticklabel", "%.2f")
>>
>> This can be done as a one-liner ...
>>
>>      set (gca, "xticklabel", sprintf("%.2f|", get (gca, "xtick")))
>>
>> However, I think it more convenient to support having the  
>> ticklabels specified as format statements.  If the y-axes units  
>> were dollars ...
>>
>>      set (gca, "yticklabel", "$%.2f")
>>
>> If the units were um
>>
>>      set (gca, "yticklabel", "%.2fum")
>
>I think this was rejected in the past because it's incompatible with  
>Matlab.  This works without introducing incompatibilities:
>
>function update_ticklabels(handle,dummy,axis);
>       fmt = get(handle, [axis, "ticklabelfmt"]);
>       labels = sprintf([fmt, "|"], get(handle, [axis, "tick"]) );
>       set(handle,[axis, "ticklabel"], labels);
>endfunction
>addproperty("xticklabelfmt",gca,"string","%g");
>addlistener(gca, "xticklabelfmt", address@hidden, "x"})
>set(gca,"xticklabelfmt","%#.2g")
>set(gca,"xticklabelfmt","%.1f")
>
>That's typed in the terminal, of course.  I see default properties in  
>src/graphics.h.in, but where would I add a default listener?
>
>Cheers,
>Rob

I like the idea of adding a ticklabelfmt property.

The current default for a linear axis is "%g". For log scale the default should 
change to "10^{%T}". A listener should be created for that as well (i.e. 
changes to xscale, yscale, zscale will produce a change to xticklabelfmt, 
yticklabelfmt, zticklabelfmt strings. To make the user specified ticklabelfmt 
stick, perhaps ticklabelfmtmode properties are also needed?

Regarding listeners, there are *many* that need to be written (units conversion 
is the best example). I've looked at the code in the hope of finding where such 
should be place, but as my c skills are very poor, I've been unable to find 
where (or if) such exists in the sources.

Ben