New plot type--submission questions

So I have a (slightly) new plot type I would like to add to the matplotlib codebase, and I'd like to ask A) if people would be interested in the patch and B) what the best way to implement it would be.

I am currently calling the plot type "pcontourf"--it's essentially a pcolor, but instead of a continuous color spectra of value, it plots discrete levels of data like contourf does. I find this kind of plot useful for model output--it displays the model grid, and also emphasizes data transitions, for example, between the negative and positive areas of a plot, better than pcolor. Essentially it is just a contourf wrapper that, instead of calling contourf with values at the 'center' of a grid cell, calls contourf with points at the edges of the grid cell so you end up with rectangular areas.

If someone is actually interested in clean this up and put it into svn, my next question is where in the codebase would be the best place to put it so I can make a clean diff file? pyplot.py? I don't quite understand how the matplotlib module hierarchy works.

Jordan

Jordan,

This sounds useful, but I think it can be implemented without any new plot type, simply by using a different sort of norm to do the colormapping. I need to add this anyway, and I have a prototype. It is very simple. I will get it in within the next few days, and then you can see whether it meets your needs.

Eric

Jordan Dawe wrote:

···

So I have a (slightly) new plot type I would like to add to the matplotlib codebase, and I'd like to ask A) if people would be interested in the patch and B) what the best way to implement it would be.

I am currently calling the plot type "pcontourf"--it's essentially a pcolor, but instead of a continuous color spectra of value, it plots discrete levels of data like contourf does. I find this kind of plot useful for model output--it displays the model grid, and also emphasizes data transitions, for example, between the negative and positive areas of a plot, better than pcolor. Essentially it is just a contourf wrapper that, instead of calling contourf with values at the 'center' of a grid cell, calls contourf with points at the edges of the grid cell so you end up with rectangular areas.

If someone is actually interested in clean this up and put it into svn, my next question is where in the codebase would be the best place to put it so I can make a clean diff file? pyplot.py? I don't quite understand how the matplotlib module hierarchy works.

Jordan

-------------------------------------------------------------------------
This SF.net email is sponsored by: Microsoft
Defy all challenges. Microsoft(R) Visual Studio 2008.
http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/
_______________________________________________
Matplotlib-devel mailing list
Matplotlib-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/matplotlib-devel

I was just working with a student to do this. It is straightforward (using norms, as Eric suggests), but not short. I think it would be good to include wrappers for creating these norms to MPL.

The advantage is then it works for everything: pcolor, scatter, etc.

-Rob

···

On Jan 31, 2008, at 12:07 AM, Eric Firing wrote:

Jordan,

This sounds useful, but I think it can be implemented without any new
plot type, simply by using a different sort of norm to do the
colormapping. I need to add this anyway, and I have a prototype. It is
very simple. I will get it in within the next few days, and then you
can see whether it meets your needs.

Eric

Jordan Dawe wrote:

So I have a (slightly) new plot type I would like to add to the
matplotlib codebase, and I'd like to ask A) if people would be
interested in the patch and B) what the best way to implement it would be.

I am currently calling the plot type "pcontourf"--it's essentially a
pcolor, but instead of a continuous color spectra of value, it plots
discrete levels of data like contourf does. I find this kind of plot
useful for model output--it displays the model grid, and also emphasizes
data transitions, for example, between the negative and positive areas
of a plot, better than pcolor. Essentially it is just a contourf
wrapper that, instead of calling contourf with values at the 'center' of
a grid cell, calls contourf with points at the edges of the grid cell so
you end up with rectangular areas.

If someone is actually interested in clean this up and put it into svn,
my next question is where in the codebase would be the best place to put
it so I can make a clean diff file? pyplot.py? I don't quite
understand how the matplotlib module hierarchy works.

Jordan

-------------------------------------------------------------------------
This SF.net email is sponsored by: Microsoft
Defy all challenges. Microsoft(R) Visual Studio 2008.
http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/
_______________________________________________
Matplotlib-devel mailing list
Matplotlib-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/matplotlib-devel

-------------------------------------------------------------------------
This SF.net email is sponsored by: Microsoft
Defy all challenges. Microsoft(R) Visual Studio 2008.
http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/
_______________________________________________
Matplotlib-devel mailing list
Matplotlib-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/matplotlib-devel

----
Rob Hetland, Associate Professor
Dept. of Oceanography, Texas A&M University
http://pong.tamu.edu/~rob
phone: 979-458-0096, fax: 979-845-6331

Eric Firing wrote:

Jordan,

This sounds useful, but I think it can be implemented without any new plot type, simply by using a different sort of norm to do the colormapping. I need to add this anyway, and I have a prototype. It is very simple. I will get it in within the next few days, and then you can see whether it meets your needs.

Eric

I assume you mean to use pcolor for this kind of plot, but with the added ability to specify levels. This doesn't do what I want; I want the ability to make large contiguous contourf-style areas outlined with contour-style lines that follow the grid edges, not the hundreds of little squares that pcolor makes. But I agree that this may not be useful enough to warrant a new plot type. I'll just keep using my hacked add-on code and if anyone else wants this kind of functionality, you can direct them to me.

Jordan