revised: How to set xtics in 2-D plot in Octave 3.0.0 on a PC with Windows Vista

[Ben Abbott]

On Feb 27, 2008, at 5:36 PM, Mr. E wrote:

> I have been using the __gnuplot_set__ xtics  command
> for a long time to set non-uniform ticks on the x
> axis, particularly handy in marking x-intercepts.
>
> The new version of Octave 3.0.0.0 does not support
> this method.  Does anyone know how to do this?
>
> here is a sample program that I have used for many
> years to teach xtic setting:
>
> xmin=0.0;
> xmax=2*pi;
> ymin=-1;
> ymax=1;
>
> deltax=(xmax-xmin)/200;
>
> axis([xmin   xmax  ymin ymax]);
> x=xmin:deltax:xmax;
> y=sin(x);
> plot(x,y)
> __gnuplot_set__ xtics ( "Pi/4" pi/4, "Pi/2" pi/2, "Pi"
> pi, "3*Pi/2"
> 1.5*pi, "2*Pi" 2*pi )
> plot(x,y)
>
>
> I already tried the suggestion on my PC Windows Vista
> with Octave 3.0.0 installation, and the
>
> set (gca, "xtick", [pi:pi/2:2*pi]);
>
> command does not change the default tickmarks.
>
> I am a teacher at a small college, and it would really
> help my students label their graphs and check handwork
> if I could get the NON-uniform tick setting working
> again.
>
> Any suggestions welcome.
>
> ps.  My question does not appear on the octave help
> page... how can I post this question there for
> everyone to see?
>
> thanks!
> Lalu
>
>
> ,¸¸,ø¤º°`°º¤ø,¸¸,ø¤º°`°º¤ø,¸¸,ø¤º°`°º¤ø
>
> Please reply to Lalu at cabrillo.edu
>
> google has good spam filtering!

I'm running 3.0.0+

This works for me in Octave and Matlab

x = linspace (0, 2*pi, 201);
y = sin (x);
xtick = 0:0.5:2.0;
xticklabel = num2str (xtick');
plot (x, y)
axis ([min(x) max(x) -1 1])
set (gca, 'xtick', xtick*pi, 'xticklabel', strcat (xticklabel, char  
(ones (size (xtick'))*'pi')))

The problem was that you specified where the tick marks were to be  
placed, but did not specify the corresponding strings.

Ben