in search of a userdir, was: plot2d cannot create maxout.gnuplot

Robert Dodier writes:
> hello vadim, you wrote:
> 
> 
>>Some write permission problem was my primary suspect.
>>And as far as I understand this is the case.  A bit
>>strange that the problem shoved up only after some
>>Windows patches but this doesn't matter.
>>The fact that Plot2/3d damps data files in some quite
>>random place is bad.  And this is actually bad on both
>>Windows and UNIX.  Especially on Windows since
>>maxout.gnuplot directory depends even on the xmaxima
>>shortcut location.  If xmaxima is invoked from
>>menu - one place, the same shortcut copied on
>>user desktop - another.  So writing maxout.*
>>files in some definite location in user's directory
>>is definitely right idea.  But I'm only not so sure
>>that maxima-userdir
>>
>>$HOME/.maxima on UNIX
>>%USERPROFILE%\maxima on Windows
>>
>>is the proper place.  As Valker mention this directory
>>may be not existent.  What about user home directory?
>>Just $HOME or %USERPROFILE% respectively.
> 
> 
> $HOME or %USERPROFILE% is OK by me.
> so is /tmp or c:\temp; however that is problematic, as it is not
> guaranteed that c:\temp exists, so far as i know.
> 
> can someone make a patch to (1) assign a userdir variable if one
> is not already assigned, and (2) modify plot2d/plot3d to write
> the output file to the user directory (whatever is decided upon) ?
> 
> when this problem is resolved, i want to go ahead with the 5.9.2 release.
> conversely, if this problem is not resolved, i am inclined to go ahead
> anyway -- a lot of stuff has changed since 5.9.1 and the benefit of
> allowing users to access the new version outweighs the lack of a
> fix for this particular problem. 
> 

I'll try to do such patch and test it on Linux,
Windows XP and Windows Me but tomorrow.

BTW Valker's plot patch reminded me about pm3d
gnuplot option (nice colored 3d plots).
What about making it true by default?
The only trouble is that it can cause
gnuplot error with older gnuplot versions
(< 4.0).  Alternatively we can turn it on
on Windows where we are sure that gnuplot
is 4.0.

-- 
      Vadim V. Zhytnikov