Re: transparent surfaces

[Tatsuro MATSUOKA]

----- Original Message -----

> From: "fibonacci4
> To: Tatsuro MATSUOKA 
> Cc: 
> Date: 2017/3/29, Wed 16:58
> Subject: Re: transparent surfaces
> 
> Am 29.03.2017 um 09:54 schrieb Tatsuro MATSUOKA:
>>  ----- Original Message -----
>>>  From: "fibonacci4
>>>  To: help-octave
>>>  Date: 2017/3/29, Wed 16:18
>>>  Subject: transparent surfaces
>>> 
>>> 
>>>  I asked this question on stackoverflow, since there I can show the 
> plots:
>>> 
> <http://stackoverflow.com/questions/43064837/octave-transparent-surfaces-how>
>>> 
>>>  I try to plot transparent surfaces in Octave using facealpha set to 
> 0.2. Ok, I have read that this is not implemented, but if I run this code, I 
> get 
> a plot with a transparent plane.
>>>  close all;
>>  clf reset;
>>  cla reset;
>>  graphics_toolkit("gnuplot");
>>  colormap(bone(64));
>>  a1=-1;b=1;h1=0.01;# making a mesh
>>  x=a1:h1:b; x2=a1:h1:b; nz2=length(x2);
>>  [X1,Y1]=meshgrid(x2,x2);
>>  Z1=zeros(nz2,nz2); # function equal to zero on the mesh
>>  s1=mesh(X1,Y1,Z1); view([120 40]);
>>  # properties of the faces and edges
>>  set(s1,'edgecolor','none')
>>  set(s1,'facecolor','black')
>>  set(s1,'facealpha',0.05)
>>  hold on
>>  scatter3([-0.5 0],[-0.5 0],[0.5 -0.5],8,'k','.');# two 
> points one above and one below the plane
>>  # print to eps
>>  print -deps testsurface.eps
>> 
>>  Doing this a plot pops up, where the plane is transparent; but the result 
> of the print command gives a non-transparent
>>  plane, the point below it cannot be seen.
>>  I tried it with fltk, same result, with qt no plane at all. I would like to 
> print it with the print command, since there are many options, size etc.
>>  Any ideas? Thanks
>>  Karl
>>  On gnuplot, postscript terminal does not support transparent surface.
>>  Thus
>>  print -deps testsurface.eps
>> 
>>  on octave does not give a transparent surface.
>> 
>> 
>>  If your gnuplot supports cairo based terminal, try
>> 
>>  print -depscairo testsurface.eps
>> 
>> 
>>  Tatsuro
> 
> Thanks Tatsuro,
> 
> Can you give me a hint, how to install the necessary  things for the cairo 
> terminal on Xubuntu 16.04?
> 
> Or would it work soemhow for fltk or qt?
> 
> Karl


Perhaps gnuplot on Xubuntu 16.04 supports cairo based terminal.

Start gnuplot on the terminal,
from gnuplot prompt

set term


Then terminal list will appear.

If you see terminals whose name has "cairo", your gnuplot supports cairo based 
terminals.

Tatsuro