[Maxima] problems with proportional plots

James Redford jrredford at yahoo.com
Sat Nov 13 12:36:03 CST 2010


Hi, Mario Rodriguez. I'm having the same problem with non-proportional plots that Christian Stengg is having.

Below is the Maxima version that I'm using:

Maxima version: 5.22.1
Maxima build date: 11:48 8/13/2010
Host type: i686-pc-mingw32
Lisp implementation type: GNU Common Lisp (GCL)
Lisp implementation version: GCL 2.6.8


When I try the below example that you gave with the wgnuplot.exe that comes with the above Maxima version, it comes out non-proportional as an ellipse with the verticle axis shorter.

However, if I use the wgnuplot.exe Version 4.4 patchlevel 2 as distributed from the Gnuplot website, it comes out proportional as a circle.


The following is the example I am referring to:

gnuplot> set parametric

        dummy variable is t for curves, u/v for surfaces
gnuplot> set size ratio -1
gnuplot> set xrange [-1:1]
gnuplot> set yrange [-1:1]
gnuplot> plot [0:2*pi] sin(t),cos(t)


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[Maxima] problems with proportional plots
Mario Rodriguez biomates at telefonica.net 
Fri Nov 12 23:37:11 CST 2010 

> Hola Mario!

Na, wie geht's?


> Except for the file path my maxout.gnuplot is exactly the same as yours 
> (I have attached it).
> 

This means that 'draw' is making its job correctly.


> > draw2d(
> >    user_preamble = "set size ratio -1",
> >    parametric(cos(t), sin(t), t,0,2*%pi)) ;
> >
> 
> With this code I get "set size noratio".

Yes, but you also get "set size ratio -1" just before the plot command,
which supersedes the default "set size noratio". Nothing wrong here.



> > What is the result when you send the output to other terminals, like
> > gif, png, eps, or wxt, with the 'terminal' option?
> >
> 
> With terminal=png I get a perfect circle.

And probably other terminals, except windows, work fine too.



> > gnuplot>  load 'path_to/maxout.gnuplot'
> >
> > what's the aspect of the curve?
> >
> 


> I get the same ellipse as in wxMaxima.

Well, I understand here when you call draw2d, not wxdraw2d, which calls
the png terminal.

I will not have access to a true Windows system until monday. Running
wgnuplot in my Linux box with 'wine' (which is a program, nothing else),
and saving wgnuplot.ini from there, the generated code is:


[WGNUPLOT]
TextOrigin=550 232
TextSize=568 768
TextMinimized=0
TextFont=Terminal,9
SysColors=0


copy this contents into your own wgnuplot.ini and let's see what
happens. 

The Gnuplot manual says:

Update wgnuplot.ini saves the current window locations, window sizes,
text window font, text window
font size, graph window font, graph window font size, background color
and linestyles to the initialization
file WGNUPLOT.INI.

But, as you can see, no information on window location and sizes was
saved. I'll try on monday again.





Let's make another test. Forget Maxima (only for one moment) and open
your wgnuplot program and repeat these steps:


gnuplot> set parametric

	dummy variable is t for curves, u/v for surfaces
gnuplot> set size ratio -1
gnuplot> set xrange [-1:1]
gnuplot> set yrange [-1:1]
gnuplot> plot [0:2*pi] sin(t),cos(t)


You should see a circle, not an ellipse. If the output is an ellipse,
the problem is definitely somewhere in your local configuration.




> Gracias por sus esfuerzos y un saludo

"sus" is too formal, let's say "tus" ;)

> 
> Christian

--
Mario


      


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