Re: gnuplot projects, terminal modules

[Daniel J S. <dan...@ie...>]

Ethan Merritt wrote:
> On Thursday 08 March 2007 04:53, Timothée Lecomte wrote:
> 
>>Dear gnuplot enthusiasts,
>>
>>Since 4.2 is out, I would like to start discussing some things I have in
>>mind for 4.3/4.4.
> 
> 
> My list (in no particular order):
> 
> 1) Continued work on internationalization
> 	- better use and documentation of LOCALE settings
> 	- support UTF-8 in as many terminal types as possible
> 	- better mechanism for integrating and maintaining localized documentation
> 
> 2) Transparency
> 	- mostly done, but needs to be implemented in win, aqua, [others?]
> 
> 3) Mousing support for SVG
> 
> 4) Mousing support for multiplot mode
> 
> 5) generate and plot 3D isosurface from 4D data
>    color-mapping a 5th value onto that surface gets us up to 5D data
> 	- splot "4D-data" using 1:2:3:4 with isosurface at <value>
> 	- splot "5D-data" using 1:2:3:4:5 with isosurface at <value>
> 
> Other projects that I'd like to see done, but I'm not the best person to
> evaluate or coordinate it:
> 
> 1) Updates to the "fit" subsystem
> 	-  1294507    Fitting using CERN Minuit routines
> 	-  1445064    Gnuplot fitting improvements
> 
> 2) Fix up the "history" command (Dan Sebald was working on this)

[ gnuplot-Bugs-1534367 ] too much expansion in FindHelp
[ gnuplot-Bugs-1525665 ] help has problems with

I believe this one is ready to go.  I recall some problems I had with a robust minor adjustment to the existing algorithm.  But then I think a did an overhaul of the general strategy for history and left it in a state I thought made sense and worked well.

Here are other items...


[ gnuplot-Patches-1566782 ] use tgamma for GAMMA() and lgamma for LNGAMMA()

I believe this works well.  Configuration goes with a library version of the routine tgamma/lgamma then falls back on gnuplot's version.  There is even use of gamma/lgamma if the global variable is valid.  I think I've cleared up the confusion with the use of that global variable and all systems are covered including MacOS (a user said it works).  Some argued there is a bug in implementations of this, but I still am not convinced the standard calls out for use of the global variable.  I think it works.


[ gnuplot-Patches-1589067 ] Alpha Channel images

People want this.  Doesn't seem difficult.  Just need time to work on it.  Ethan has it pretty much figured out and put together a patch.


term->clip_region (or whatever)

Ethan suggested a clip region for the terminal.  Lines/images/polygons/etc would then be clipped to this region.  That would move an extraneous set of coordinates from the term->image function.


[ gnuplot-Patches-1636431 ] Allow hidden3d with pm3d and rename to 'tileline' option

This patch was simply a means of improving the sorting depth approach to hidden surface elements which is only an estimate.  I don't think this patch itself will yield too much.  However, I think there is a TODO item here and that is to utilize the hidden mesh code in combination with the pm3d elements.  I think this might fit together better and more easily than people realize.  There would be a couple things:

1) Clean up the current hidden 3D code.  I see little vestigial bits of lines and corners in some of the hidden 3D examples.

2) After that, then come up with a robust hidden surface routine (in the above patch are some short 3D matrix inverse and hyperplane routines that could be useful), and then overlay the hidden 3D mesh.


[ gnuplot-Bugs-1488168 ] z_floor and z_ceiling based on xyplane.absolute

This is an outright bug fix.  It should have gone in 4.2 had there been a little time to review it.  The only thing required is a reviewer to say "Hey, I don't like that nonlinear mouse movement behavior, I'd rather it be linear", or "Nonlinear is better than linear."


[ gnuplot-Patches-1523316 ] improved CLIPBOARD and PRIMARY per X conventions

This one I think is a big winner.  There's a bit of code there, but it is a full implementation of mouse/clipboard behavior consistent with the vast majority of X applications.


[ gnuplot-Bugs-1004754 ] Tics and grid slightly outside border

This was a case where a double tic would appear at the end of an axis because of rounding effects.  I believe the approach I used works well, but people didn't seem to buy it.  It's rather simple really: "integerize" the tics rather than looping until the tic value falls out of range.  That is, because of the integer nature we can tell when we are at the end of the range, i.e., the last possible tic.  Then if at the last tic we test

  last_tic < end_range

rather than the current approach (i.e., effect of looping)

  first_tic + delta_tic + delta_tic + ... + delta_tic < end_range

The second approach is susceptible to rounding, the first isn't.  I.e., the existing problem is that last_tic is greater than end_range (and the tic shouldn't be printed), but first_tic + delta_tic + ... + delta_tic is less than end_range (and the tic ends up being printed).


[ gnuplot-Patches-1508316 ] Allow multiple strings to signify "missing"

This code could be used.  (There is a demo which illustrates different behavior.)  I think mostly though this is about coming up with coherent method of handling these "data special exceptions" that was never formally considered, i.e., I think it used to be what you get is what you get.


[ gnuplot-Patches-1027032 ] Connect gnuplot_x11 to exterior application window

Works as far as I know.  X11 has an issue whereby two resources both controlling the mouse in a window will cause an error.


Allow multiple palettes on a multiplot X11 window

This is that problem where someone plotted a multiplot having two different palettes.  It works on all terminals except X11.  An X11 window only allows one palette.  I think the best way to deal with this is to have individual X11 windows for the subplots that lies on top of the base plot X window.  That way each window can have its own subplot and its own palette.


Review the image placement

We should review how image places the start of the bounding box and possibly make it consistent with any existing conventions.  It may be off by half a pixel.  Petr suggested possibly having an option so images can have the position in the center of the pixel or the lower left corner.  After addressing that, then go through each of the terminals and verify consistency, e.g., GIF, etc.


Unify plot layout for 2D and 3D

This was discussed with Mike Sutton on the list.  A bit of work.


Place all plot information in structures

Hans suggested this a long time ago so that multiplots and all plot may be redrawn freely.  (One utility I know of simply launches multiple versions of gnuplot to hold information unique to individual plots.)


Probably forgot some...

Dan