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Is there anyway to place the tick marks so that they are located 
outside the axes, i.e. on the same side of the axis line as the axis 
labels?

With plots such as imshow and pcolor and even some busy line plots, the 
interior minor ticks are completely obscured and the exact location of 
the major ticks is ambiguous.

It would be nice to be able to specify the ticks as inside or outside 
(or both), right or left (or both), top or bottom (or both). This 
functionality may already be present but I cannot figure out how to 
invoke it if it is.

--Jim

To reply to my own post:
On question (1):
I modified the call to colorbar in pylab.py to accept a color map and 
norm keyword arguments. It was this functionality that was needed from 
the mappable image. So if the keywords are provided colorbar uses them, 
otherwise it looks for a mappable image.
This modification disables the observer feature for now if the color 
map is a keyword, a bit more work should get this going.
It looks like it would be easily doable, but I need something for the 
exigencies of work and will get back to this later.
This also would allow for a colorbar key for coloring contours and 
vectors.
I would also like to code up a floating color bar. Often I make 4/5 
images per page with a common colormap and normalization. It is
handy just to plop the reference colorbar in a central location not 
attached to a particular figure.

On question (2):
Alan Isaac pointed out that using the same edgecolor as the fillcolor 
would make the borders invisible.


--Jim

On Jan 12, 2005, at 12:55 PM, James Boyle wrote:

> I have a mesh of irregular polygons, like a finite element mesh. Each 
> polygon has an associated value.
> So, I have defined a color map with a appropriate normalization to 
> define a color for each value and then
> built a collection consisting of the polygon vertices and colors.
> The resulting plot looks pretty good. This technique would seem to be 
> useful for FE grids and Delaunay triangles.
>
> Two questions:
> (1) I want to attach a colorbar to the figure, but as of yet I have 
> not worked out how to do it.
> images such as scatter, imshow, pcolor are mappable and will accept a 
> color bar but my simple polygon fill will not.
>
> (2) How do I eliminate the edge lines about each polygon? I can make 
> them very thin but a width of zero does not appear to work.
> I recall this being discussed on the list, but now I cannot find the 
> reference.
>
> Thanks for any help.
>
> --Jim
>
>
>
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As you know you must set 'shape' attribute
of your coordinate arrays used to generate a pcolor plot.

Imagine your arrays had points (Cartesian position vectors)
all over the place at completely random points in space.
The 'shape' of this plot depends on max and min values
of each coordinate.  I believe Mathematica plotting
would automagically calculate these max and min values
and set plot ranges for you.  This is why 'shape'
attribute of Matplotlib/Numarray seems awkward
and unnecessary to me unless I'm missing something.

You should not have ability to set 'shape' your self.
It seems it wouldn't make any sense to *change* the
shape since that is decided by range of your values
already.

Chris
--
_______________________________________

Christian Seberino, Ph.D.
SPAWAR Systems Center San Diego
Code 2872
49258 Mills Street, Room 158
San Diego, CA 92152-5385
U.S.A.

Phone: (619) 553-9973
Fax  : (619) 553-6521
Email: seb...@sp...
_______________________________________

I'm still confused about 'shape' attribute of
arrays used to make a pcolor plot.

Suppose you have xarray, yarray and zarray.
The 'shape' of the plot is determined by
the max and min values of each dimension.
Hence you can't really change the 'shape'
of a plot drastically.

Therefore, what does it mean when we set and
later change the 'shape' attribute of these
data arrays?

It seems you should not be allowed to do this
and/or perhaps shape should be calculated
automatically.

Chris

--
_______________________________________

Christian Seberino, Ph.D.
SPAWAR Systems Center San Diego
Code 2872
49258 Mills Street, Room 158
San Diego, CA 92152-5385
U.S.A.

Phone: (619) 553-9973
Fax  : (619) 553-6521
Email: seb...@sp...
_______________________________________

On Wed, 12 Jan 2005, James Boyle apparently wrote: 
> (2) How do I eliminate the edge lines about each polygon? I can make
> them very thin but a width of zero does not appear to work.
> I recall this being discussed on the list, but now I cannot find the
> reference.

I recall John suggesting to also set the edge color (to the
same color, of course).  I hope a true zero width will
implemented.

However note that interpreting a linewidth of zero as a 1
pixel wide line is what PostScript does.  So the only way to
get a true zero width for PostScript output is to fill the
polygon without stroking it.

hth,
Alan Isaac