Contour plots

Perry Greenfield wrote:

    >>> Actually, I believe that the low level contour engine we are
    >>> using supports this. It takes 2-d arrays for both x and y that
    >>> represent the x and y coordinates of the array being contoured
    >>> and generates plotting points based on those x and y
    >>> arrays. These arrays allow for irregular grids.

    > completely irregular? or only orthogonal structured
    > grids. From your description, it sounds like the
    > later. Could it take an unstructured set of (x,y,z) points
    > and contour the z values?

The latter, I believe. The contouring routine was implemented by
Nadia Dencheva (CCd on this mail) and is based on a gist routine. You
can read more about the core routine at
http://scipy.net/cgi-bin/viewcvsx.cgi/checkout/scipy1/xplt/src/gist/gcntr.c?rev=HEAD&content-type=text/plain.

The contour routines have been checked into CVS. A simple example can
be found in examples/contour_demo.py in CVS. We have some rudimentary
support for labeling (auto-legend and/or brute-force use of the text
command). It would be nice to develop a point and click labeling
widget and/or an auto-labeling routine. Contributors of course always
welcome!

JDH

John Hunter Wrote:

    > Perry Greenfield wrote:

    >>> Actually, I believe that the low level contour engine we are
    >>> using supports this. It takes 2-d arrays for both x and y that
    >>> represent the x and y coordinates of the array being contoured
    >>> and generates plotting points based on those x and y
    >>> arrays. These arrays allow for irregular grids.

    > completely irregular? or only orthogonal structured
    > grids. From your description, it sounds like the
    > later. Could it take an unstructured set of (x,y,z) points
    > and contour the z values?

The latter, I believe. The contouring routine was implemented by
Nadia Dencheva (CCd on this mail) and is based on a gist routine. You

Yes, the latter. For an unstructured set some other approach would be
needed. Sorry if I misunderstood. I thought what was being discussed
was irregular spacings rather than irregular organization.

Perry

John Hunter wrote:

"Chris" == Chris Barker <Chris.Barker@...259...> writes:

    > completely irregular? or only orthogonal structured
    > grids. From your description, it sounds like the
    > later. Could it take an unstructured set of (x,y,z) points
    > and contour the z values?

The latter, I believe.

yup. from the below referenced link:

"""
General purpose contour tracer for quadrilateral meshes.
"""

So it won't handle arbitrary unstructured points, but it's nice none the less. With an interpolator to a rectangular grid, you could use it for any array of points, I think someone posted an example of this on the matplotlib list.

-Chris

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