comp.lang.idl-pvwave archive - RDF feed
type: channel
description: Messages from Usenet group comp.lang.idl-pvwave, compiled by Paulo Penteado
items: Map_image questions
items: Re: map_image

Map_image questions
type: item
description: I have a question concerning the Idl routine map_image. I have an image of a 2d field, however the data is valid only over continents, and not the sea. The data values for points over the sea are there they are just not valid and are not flagged with any convenient missing data flag. When I use map_image to warp this image onto a specific map projection the bad sea values are interpolated with the good continental values thus causing the values on the continental outlines to be compromised. Is there a way around this? Does anyone have a map_image like routine that will only interpolate a selected range of valid data values? Is something like this possible/easy to write? I'm open for suggestions. Thanks --Joe || Joe Doetzl | Climate Modeling Section || || doetzl@pendragon.cgd.ucar.edu | National Center for Atmospheric Research || || doetzl@ncar.ucar.edu | Boulder, Colorado (303) 497-1319 ||
creator: doetzl
date: 1993-08-27T17:37:03-00:00

Re: map_image
type: item
description: In article <2o1kru$okb@paperboy.gsfc.nasa.gov> fisher@echo.gsfc.nasa.gov (Brad L. Fisher) writes: > ............................................ My question then is how do > I get map_image to return the image with the map overlayed. Any help would > be greatly appreciated. hello, well, as you realized, map_image just returns the image that can now be displayed over your map (created with map_set). First, create your map via map_set, creating continents, etc to your liking. Then call map_image like the following: wrapped_image = map_image(image,startx,starty,latmin = latmin, latmax=latmax,lonmin=longmin, lonmax=longmax) then to display this on top of your map, do the following: tv,wrapped_image,startx,starty then you may need (want) to redraw the grids or continents with map_grid and map_continents. Oh, just noticed almost this exact example is in the reference guide under map_image. If your question is how do you get the entire new image and the map into one image, read it back from the screen with tvrd once you put it all together. Or if you don't ever want it to appear on the screen, use a pixmap instead of a visible window. hope this helps, good luck, -stephen -- Stephen C Strebel / SKI TO DIE stl@maz.sma.ch / and Swiss Meteorological Institute, Zuerich / LIVE TO TELL ABOUT IT 01 256 93 85 / (and pray for snow)
creator: stl
date: 1994-04-08T07:47:30-00:00