Hi,
I ran into the following problem with map_grid (with IDL 4.0.1b on Linux):
map_set, 50., 0., /stereo, /iso, /grid, /cont
works as expected (by me), producing a north polar stereographic projection
with the Greenwich meridian centered, continent outlines and a grid
with meridians every 45 degrees. BUT using
map_set, 90., 30., /stereo, /iso, /grid, /cont
creates a correctly rotated map with the 30E meridian pointing downwards,
but the grid has _not_ been rotated. Thus, continent outlines are plotted
correctly, but not the grid lines.
For a stereographic projection, the rot parameter is a possible workaround;
map_set, 90., 0., 30., /stereo, /iso, /cont, /grid
produces what I need.
When using the orthographic projection, however, I'm somewhat lost:
map_set, 50., 0., /ortho, /iso, /cont, /grid
generates the desired view of the globe from above the Greenwich meridian.
map_set, 50., 30., /ortho, /iso, /cont, /grid
generates the same but centered above 30E; with correct continents, but
an unrotated longitude/latitude grid. Obviously, the rot parameter does not
help here, as it rotates (roughly) the earth's axis. Worse, the latitudes
do not coincide with 'reasonable' ones (like the equator).
Does anyone know of a possible workaround? Might there even be a routine
available to draw specified longitude and latitude lines based on the current
map projection?
Thank you very much,
Chris Marquardt (marq@strat01.met.fu-berlin)
draw specified longitudes / latitudes
|
comp.lang.idl-pvwave archive
Members
Search
Help
Login
Home
