[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Contour plots on maps

Hi Simon,

   what helped me often in these situations is to make sure that the
data and
your map projection are "aligned" correctly, i.e. for a regional plot
(using the 
LIMIT keyword to MAP_SET) you shouldn't have (much) more data than what
fits onto
the map, and in case you wrap your map around the dateline or play
similar tricks,
you should also shift your data accordingly. Although CELL_FILL covers
many of these
situations, I still consider it a somewhat dirty trick and I am only
happy after my plots appear similar with or without CELL_FILL.

David: here is what could be the tip of the year 2000 (although not as
simpel and short as the decomposed thing): "Why are my (filled) contours
so messy?"


Simon de Vet wrote:
> David Fanning wrote:
> > There are several articles that you will really want to
> > read on my web page, but I would start with this one,
> > because you definitely have "holes" in your contour plots:
> I found this site, and already have incorporated the solution into my code.
> If I plot my filled contours without a map projection, it plots beautifully,
> with no holes or gaps.
> This is the problem: first, the lowest few contours are filled in. Then they
> are all overwritten in white, and the next are filled in. These are also
> whited out, and the last couple are plotted. Only the last ones are visible
> when the plotting is complete.
> I am outputting all my plots to postscript files, and not to the screen
> I have also tried changing the centre of the plot, as you mentioned, so that
> the data border corresponds to the plot border (Greenwhich on the edge,
> instead of the middle.) This eliminates the odd diagonal lines, but does
> nothing to the filled contour troubles.
> These problems occur for all map projection types, and never if map
> projection is turned off.
> Simon

[[ Dr. Martin Schultz   Max-Planck-Institut fuer Meteorologie    [[
[[                      Bundesstr. 55, 20146 Hamburg             [[
[[                      phone: +49 40 41173-308                  [[
[[                      fax:   +49 40 41173-298                  [[
[[ martin.schultz@dkrz.de                                        [[