Michael Hearne wrote: > Jeff - > > My data set is actually dynamically generated by a program called > ShakeMap. It's a 2D grid, with an extent usually about 600 kilometers > on a side, centered wherever the earthquake happened to be. The > ShakeMap program does not know or care that some of the data may be > under water, but for display purposed, I do! The grid is also in a > geographic projection (latitude/longitude coordinates assumed to be > cartesian). Michael: You'll either have to create your own land-sea mask, or use Pierre's method with gdal. > > So in this test instance (on a data set near Taiwan), my map width is > about 5.91 degrees longitude, and my height is about 5.5 degrees latitude. > > If I set xoffset=-0.01*5.91, I get -0.05. This is not noticeably > different than the default. > > Is the problem that my dataset is not projected? What is m.xmax-m.xmin? (m is the basemap instance, xmin and xmax are instance variables) That's what you have to use - the distance in map projection coordinates, not lat/lon coordinates (although these will be the same if you are using projection='cyl').
-Jeff > > --Mike > On Nov 2, 2007, at 1:33 PM, Jeff Whitaker wrote: > >> Michael Hearne wrote: >>> Jeff - I looked at that example file, and I think there's a big >>> difference - your etopo base data set is global, and you can plot >>> over the data in the oceans by setting the mask on all pixels less >>> than zero. >>> >>> My dataset (a map of earthquake shaking) is not global, and actually >>> has NO missing data. I think I need a way to "clip" the data by >>> the land mask - that is, find all of the pixels that are NOT on >>> land, and then mask them off. >> Mike: >> >> If it's not global, is it just defined for land points? If so, it >> can't be a 2-D grid, so you won't be able to plot it with imshow >> anyway. Can you explain the structure of the data? >>> >>> Is there an easy way to do this with matplotlib/basemap tools? >> Not really. You'll have to define a sea mask for your grid and use >> that the create a masked array. There is a land-sea mask dataset >> included in basemap, but it may not match the resolution of your grid. >> >>> >>> Regarding my other issue - I used my script to test x/y offset >>> values: [0.05,0.1,0.5,1.0,10] and couldn't see any difference. I'd >>> be more than happy to provide test output, or debugging information... >>> >>> Just to be clear - these offsets are supposed to move the meridian >>> and/or parallel labels around with respect to the map edge? My >>> actual goal is to get the labels inside the edge of the map (I tried >>> negative numbers to accomplish this, to no effect.) >> You need to define an offset as a fraction of the map width - the >> numbers you are giving are too small to notice any difference. As I >> said before, try something like -0.01*(m.max-m.min). >>> >>> On a positive note, I _can_ make solid lines! >> >> Good! >> >> -Jeff >> >> -- >> Jeffrey S. Whitaker Phone : (303)497-6313 >> Meteorologist FAX : (303)497-6449 >> NOAA/OAR/PSD R/PSD1 Email : [EMAIL PROTECTED] >> <mailto:[EMAIL PROTECTED]> >> 325 Broadway Office : Skaggs Research Cntr 1D-124 >> Boulder, CO, USA 80303-3328 Web : http://tinyurl.com/5telg > > > > > ------------------------------------------------------ > Michael Hearne > [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]> > (303) 273-8620 > USGS National Earthquake Information Center > 1711 Illinois St. Golden CO 80401 > Senior Software Engineer > Synergetics, Inc. > ------------------------------------------------------ > > -- Jeffrey S. Whitaker Phone : (303)497-6313 NOAA/OAR/CDC R/PSD1 FAX : (303)497-6449 325 Broadway Boulder, CO, USA 80305-3328 ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
