# coyote: CGFINDMAPBOUNDARY

- coyote/Utilities
- [Source code]

Description

      Utility routine to find the map projection grid boundary from a file,
      if it is possible to do so. Currently works with GeoTIFF files, CF 1.4
      compliant netCDF files, and GPD files created with the GPD_Viewer software
      from the Catatlyst Library.

Categories

      Utility

Returns

      The return value is either a 1, indicating a boundary can be found, or a 0 indicating
      that the boundary could not be found.

Params

      filename: in, required, type='string'
         The name of a filename to open to see if a projected map grid boundary can be found.
      boundary: out, optional, type=float
         The boundary of the image in projected meter space, in the form [x0,y0,x1,y1].

Keywords

      use_latlon:  in, optional, type=boolean, default=0
          If the filename is a netCDF file, set this keyword to force the boundary
          to be determined by reading the include latitude/longitude arrays.
      utm_south: in, optional, type=boolean, default=0
          Set this keyword to add 10e6 to each of the Y values. This is sometimes
          necessary with LandSat images in the Southern hemisphere, where the Y values
          are given in negative values to indicate southern UTM zones.
      xrange: out, optional, type=float
          A two element vector: boundary[[0,2]]
      yrange: out, optional, type=float
          A two element vector: boundary[[1,3]]

Author

      FANNING SOFTWARE CONSULTING::
         David W. Fanning
         1645 Sheely Drive
         Fort Collins, CO 80526 USA
         Phone: 970-221-0438
         E-mail: david@idlcoyote.com
         Coyote's Guide to IDL Programming: http://www.idlcoyote.com

History

      Written by: David W. Fanning, 23 February 2010.::
         Added XRANGE and YRANGE keywords. 25 February 2010. DWF
         Added USE_LATLON keyword for finding boundary of netCDF files containing latitude
            and longitude arrays. 6 April 2010. DWF.
         Added UTM_SOUTH keyword to handle Landsat dat in UTM projections in GeoTiff files
            that have to have 10e6 added to Y values to make them work in IDL. 14 Aug 2012. DWF.
         Renamed cgFindMapBoundary from FindMapBoundary. 21 Aug 2012. DWF.
         Changed reference to NCDF_Coord to cgNCDFMap. 28 Oct 2012. DWF.

Copyright

      Copyright (c) 2012, Fanning Software Consulting, Inc.