Re: support for advanced gnuplot features (was: Plotting semi-trasnparent patches?)

[Ben Abbott]

On Monday, January 26, 2009, at 12:01PM, "Kai Habel" <address@hidden> wrote:
>Ben Abbott schrieb:
>> On Monday, January 26, 2009, at 10:12AM, "Kai Habel" <address@hidden> wrote:
>>   
>>> Soren Hauberg schrieb:
>>>     
>>>> Hi All
>>>>
>>>> Is there a way to make a patch (as produced by the 'patch' command)
>>>> semi-transparent? I tried setting the 'facealpha' property to 0.5 but
>>>> that didn't do what I expected.
>>>>
>>>> BTW. I'm running a checkout of the development sources from some time
>>>> yesterday.
>>>>
>>>> Soren
>>>>
>>>> _______________________________________________
>>>> Help-octave mailing list
>>>> address@hidden
>>>> https://www-old.cae.wisc.edu/mailman/listinfo/help-octave
>>>>   
>>>>       
>>> Using a development version of gnuplot (4.3.cvs) this can be implemented
>>> fairly easy. See attached patch. I am hesitating in providing a full
>>> changeset, since we would depend on a development version of gnuplot. I
>>> see no easy way to check for this gnuplot feature otherwise we could
>>> support this conditionally. I think we have to wait for gnuplot release
>>> which supports this feature. 
>>>
>>> Kai
>>>
>>> diff -r 0eb83938c8bc scripts/plot/__go_draw_axes__.m                        
>>>   
>>> --- a/scripts/plot/__go_draw_axes__.m   Sun Jan 18 22:01:36 2009 +0100      
>>>   
>>> +++ b/scripts/plot/__go_draw_axes__.m   Mon Jan 26 16:02:02 2009 +0100      
>>>   
>>> @@ -568,8 +568,8 @@                                                         
>>>   
>>>               if (mono)                                                     
>>>  
>>>                 colorspec = "";                                             
>>>  
>>>               else                                                          
>>>  
>>> -                colorspec = sprintf ("lc rgb \"#%02x%02x%02x\"",           
>>>   
>>> -                                     round (255*color));                   
>>>   
>>> +                colorspec = sprintf ("lc rgb \"#%02x%02x%02x\" fillstyle 
>>> transparent solid %f",
>>> +                                     round (255*color), obj.facealpha);    
>>>                     
>>>               endif                                                         
>>>                    
>>>               withclause{data_idx} = sprintf ("with filledcurve %s",    
>>>
>>>     
>>
>> Kai,
>>
>> I think it makes sense to start a discussion about what version of gnuplot 
>> will be required by the upcoming 3.2 release and whether or not conditional 
>> support for more recent gnuplot builds should be included.
>>
>> For example, I have a local copy of gnuplot_drawnow that respects 
>> set(gcf,"position") for the x11 terminal (both window position and size are 
>> respected). My patch requires a very recent build of the gnuplot developers 
>> sources (it should also work with 4.2.4+).
>>
>> Regarding conditional support, this is easily done by using 
>> __gnuplot_version__() and compare_versions().
>>
>> Ben
>>
>> p.s. for this context, I've switched to address@hidden
>>
>
>But __gnuplot_version__ gives just:
>octave:1> __gnuplot_version__
>ans = 4.3.0
>octave:2>
>
>So, what is missing here is the actual checkout date. We can not
>determine reliably whether this cvs checkout does support a feature or not.

I agree, we are missing the checkout date, but I'm not sure about checking for 
it. As it would only be useful for developers of octave/gnuplot, I think it is 
safe to assume those running 4.3 (developers sources) are able to keep their 
gnuplot up to date.

>I think we should require the most recent release version of gnuplot
>(4.2.4) for the octave development tree. If we can *safely* determine
>features of the gnuplot development tree (4.3), those could be supported
>too. But I would do this on case-by-case basis.

My understanding is that 4.2.4 is required for the developers sources ... 4.2.3 
will work but not display 3D plots correctly with shading("interp").

>I think it is o.k. to require for a new octave release the most recent
>release of gnuplot (4.2.4 at the moment). But others might see this
>different.
>
>Kai

I'd also like see the conditional support for these improvements (figure 
position and facealpha) added to the gnuplot backend.

Is there a reason why we wouldn' t want to do that?

Ben