request: figaspect API change

Could it be changed such that figaspect takes a float

    > as its argument and the 2 lines to compute arr_ratio
    > are moved from figaspect to matshow before calling
    > figaspect ? (+ change the figaspect doc string) It will
    > make figaspect more general and allow us to create a
    > figure with a given aspect ratio without
    > copying/pasting of nearly all the figaspect machinery.

Good idea -- I overloaded figaspect to do both (it works with either
an array or a number argument). Code is below and in CVS

    Checking in lib/matplotlib/;
    /cvsroot/matplotlib/matplotlib/lib/matplotlib/,v <--
    new revision: 1.34; previous revision: 1.33

    > 2/ Does anybody intend to add a Patch object to draw
    > polygons with holes (I do not know how to do it) ?

Not presently, but this would be nice.


def figaspect(arg):
    Create a figure with specified aspect ratio. If arg is a number,
    use that aspect ratio. If arg is an array, figaspect will
    determine the width and height for a figure that would fit array
    preserving aspcect ratio. The figure width, height in inches are
    returned. Be sure to create an axes with equal with and height,

    Example usage:

      # make a figure twice as tall as it is wide
      w, h = figaspect(2.)
      fig = Figure(figsize=(w,h))
      ax = fig.add_axes([0.1, 0.1, 0.8, 0.8])
      ax.imshow(A, **kwargs)

      # make a figure with the proper aspect for an array
      A = rand(5,3)
      w, h = figaspect(A)
      fig = Figure(figsize=(w,h))
      ax = fig.add_axes([0.1, 0.1, 0.8, 0.8])
      ax.imshow(A, **kwargs)

    Thanks to Fernando Perez for this function

    isarray = hasattr(arg, 'shape')
    # min/max sizes to respect when autoscaling. If John likes the idea, they
    # could become rc parameters, for now they're hardwired.
    figsize_min = array((4.0,2.0)) # min length for width/height
    figsize_max = array((16.0,16.0)) # max length for width/height
    #figsize_min = rcParams['figure.figsize_min']
    #figsize_max = rcParams['figure.figsize_max']

    # Extract the aspect ratio of the array
    if isarray:
        nr,nc = arg.shape[:2]
        arr_ratio = float(nr)/nc
        arr_ratio = float(arg)

    # Height of user figure defaults
    fig_height = rcParams['figure.figsize'][1]

    # New size for the figure, keeping the aspect ratio of the caller
    newsize = array((fig_height/arr_ratio,fig_height))

    # Sanity checks, don't drop either dimension below figsize_min
    newsize /= min(1.0,*(newsize/figsize_min))

    # Avoid humongous windows as well
    newsize /= max(1.0,*(newsize/figsize_max))

    # Finally, if we have a really funky aspect ratio, break it but respect
    # the min/max dimensions (we don't want figures 10 feet tall!)
    newsize = clip(newsize,figsize_min,figsize_max)
    return newsize

Thank you,