Any Octave/Matlab folks on the list?

GNU Radio
1

I have some X,Y,Z data that I want to turn into a gray or colour mapped
contour plot.

The data aren’t necessarily gridded, so I need interpolation.

I’m a newbie to Octave/Matlab, and could use a hint.

I’ve played with contourf(), which I can make work for functions, but I
need to load external data that is
organized as columns of X,Y,Z in ascii.

2

On 11/29/06, Marcus L. [email protected] wrote:

I have some X,Y,Z data that I want to turn into a gray or colour mapped
contour plot.

The data aren’t necessarily gridded, so I need interpolation.

I’m a newbie to Octave/Matlab, and could use a hint.

I’ve played with contourf(), which I can make work for functions, but I
need to load external data that is
organized as columns of X,Y,Z in ascii.

A quick google search revealed a nice and informative page:

http://www2.ohlone.edu/people2/bbradshaw/matlab/plotting3dsurfaces.html

You can use the load command to get the data into Matlab for
manipulation.

Brian

3

Marcus L., el 11/29/06 22:12:

I have some X,Y,Z data that I want to turn into a gray or colour mapped
contour plot.

The data aren’t necessarily gridded, so I need interpolation.

I’m a newbie to Octave/Matlab, and could use a hint.

I’ve played with contourf(), which I can make work for functions, but I
need to load external data that is
organized as columns of X,Y,Z in ascii.

For cases like this, I prefer to plot straight in gnuplot instead of
going
through octave. There are some examples here:

http://gnuplot.sourceforge.net/demo_4.1/contours.html

I have some gnuplot files for plotting 3D functions around, let me know
if you’d
like to take a look.

–
Miguel Bazdresch Sierra

4

L. Miguel Bazdresch Sierra wrote:

organized as columns of X,Y,Z in ascii.

For cases like this, I prefer to plot straight in gnuplot instead of
going through octave. There are some examples here:

For what it’s worth, I’ve found a tool called “grace”
(plasma-gate.weizmann.ac.il/Grace/) to be really useful. It seems to be
more flexible than gnuplot, and has both a WYSIWYG graphical interface
and a batch-driven one. With a little ugly perl wrapped around the
batch function, I’ve been able to automate the production of nice
looking graphs for my web site.

John

5

For what it’s worth, matplotlib http://matplotlib.sourceforge.net/
produces beautiful contour plots. It is python based and easy to use.

–Ryan