Re: status of alternatives to linetype/pointtype?

[Ethan A M. <merritt@u.washington.edu>]

On Monday 12 November 2007 13:58, Ralf Juengling wrote:
> 
> On Mon, 12 Nov 2007, Ethan A Merritt wrote:
> 
> > As to lines and the choice of existing point types, it has been
> > fully supported since the release of version 4.2 early this year.
> >
> > See for instance:
> > 	http://gnuplot.sourceforge.net/demo_4.2/dashcolor.html
> > 	http://gnuplot.sourceforge.net/demo_4.2/rainbow.html
> >
> 
> Thanks. I have already discovered and used user defined line styles.
> What I was referring to, though, is the line or point pattern that
> is chosen per "linetype" or "pointtype", respectively. Even if one
> defines his own line style like in "dashcolor.dem",
> 
> set style line 1 lt 2 lc rgb "red" lw 3
> 
> this is not completely terminal independent because the meaning
> of "lt 2" is terminal dependent (I'm aware that also rgb is not
> supported by all terminals).

Color and width:
Obviously if the terminal cannot draw color, then nothing gnuplot
does will change that.  If you define a set of line styles with
explicit rgb colors, or simply "lt -1" (black), then they are 
terminal independent up to the point that the physical output
device supports it.

> > If you mean user definition of point types, please ask a more
> > specific question.
> 
> The same holds for point types, as far as I understand (applies
> to plotting styles 'points' or 'linespoints'). It would be nice
> if the interpretation of point types were terminal independent.

Points:
The first 8-10 point types are supposed to be the same up to the
limitations imposed by individual output hardware.  
I've just checked on post/pdf/cairo/png/emf/latex/x11/wxt/win 
They all look pretty much equivalent to me.
Do you have an example of an inconsistency?


Dashes:
I am not aware of any standard definition of dash patterns that
would be terminal-independent in the sense that RGB color is.
I am dubious that we can do any better than we already are.
The following terminals types have some hope of doing similar
things:

post, pdf  The patterns for PostScript and PDF output are defined
           equivalently in gnuplot; the various rendering programs may
           not produce the same output, however.   
cairo      We're still fiddling with the pattern definitions in the new
           support in the current cairo library is not satisfactory.
x11        Defined by your local X11 Resources file

So far as I know, we have little to no control over dash patterns on
other terminals.  If you know otherwise, please submit a patch 
demonstrating how this would work.
 


> > Some options are available there also.
> > See for example the 2nd to last plot of:
> > 	http://gnuplot.sourceforge.net/demo_4.2/stringvar.html
> 
> Thanks. I was not aware of the possibility of using symbols
> from a user-specified font. How is that implemented, though?
> If I create an eps, say, using symbols from user-defined fonts
> for some labels, do I need those fonts installed on the
> machine that I use for viewing/rendering the eps with?

If you simply refer to the font by name, then it must be installed
on the viewing machine or printer. However, you can use the
"fontfile" option to embed the font in the output file. Then there
is no need for a separately installed copy.

Embedding an entire font makes for a large output file, however.
For this purpose it would be better to use symbols from a small font
containing only the symbols you want.  You may be able to use the
"-L" option to the program "ttf2pt1" to create such a minimal font.
I'm still learning to use it myself, so I can't offer more detailed
instructions.


-- 
Ethan A Merritt