FW:Re: transparent surfaces

[Tatsuro MATSUOKA]

This is forwarded message to help-octave list.


Tatsuro

Am 29.03.2017 um 10:29 schrieb 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
> 
Thanks Tatsuro,

my gnuplot shows "epscairo" as terminal, but when I use it, there comes an 
error message:  "cannot find device profile".

But I tried then "dpdfcairo" and this works!! So I have now a solution.

Karl