[gdal-dev] "gdalwarp -te " units of source or target srs?

[chapmanm at pixia.com]

Matt,

I am guessing here, but negative values for a linear coordinate system sound wrong.  For an angular coordinate system (i.e. Wgs84) that use decimal degrees it would be correct but for a projected system I thought the purpose of a false easting and false northing was to avoid negative values?

Martin

------Original Message------
From: Matt Wilkie
Sender: gdal-dev-bounces at lists.osgeo.org
To: gdal-dev at lists.osgeo.org
Sent: Nov 19, 2008 3:27 PM
Subject: [gdal-dev] "gdalwarp -te " units of source or target srs?

Hello,

With regards to gdalwarp target_extent parameter, are the coords for the 
target coordinate system or the source coordinate system?
from http://www.gdal.org/gdalwarp.html:

    -te xmin ymin xmax ymax:
        set georeferenced extents of output file to be created.

I ask because I'm getting "ERROR 1: Attempt to create 11158x-7438 
dataset is illegal,sizes must be larger than zero." and I don't know 
whether it's because both the source and targe SRS have negative coords 
in their extent or my clipping coords are out of bounds or something else.

gdalwarp -t_srs %dst_proj% in.tif out.tif -te -2949.031, 1322540.680 
1002042.239,  652516.412
Creating output file that is 11158P x -7438L.
ERROR 1: Attempt to create 11158x-7438 dataset is illegal,sizes must be 
larger than zero.

gdalinfo in.tif
...snip
Upper Left  ( -500395.349, 1930874.566) (159d17'52.58"W, 69d54'34.69"N)
Lower Left  ( -500395.349,   -6735.434) (147d27'23.12"W, 53d20'24.33"N)
Upper Right ( 1556734.651, 1930874.566) (104d22'44.55"W, 69d41'49.51"N)
Lower Right ( 1556734.651,   -6735.434) (116d44'4.97"W, 53d13'1.10"N)
Center      (  528169.651,  962069.566) (131d56'26.40"W, 63d 8'54.60"N)

gdalinfo out_tif_template.tif
...snip
Upper Left  (   -3009.232, 1322710.243) (152d 7'23.36"W, 65d59'29.18"N)
Lower Left  (   -3009.232,  652571.483) (150d 2'48.82"W, 60d 3'7.24"N)
Upper Right ( 1002049.121, 1322710.243) (129d53'51.55"W, 65d59'34.53"N)
Lower Right ( 1002049.121,  652571.483) (131d58'12.52"W, 60d 3'11.61"N)
Center      (  499519.945,  987640.863) (141d 0'34.57"W, 63d22'43.99"N)


thanks,

-- 
matt wilkie
--------------------------------------------
Geographic Information,
Information Management and Technology,
Yukon Department of Environment
10 Burns Road * Whitehorse, Yukon * Y1A 4Y9
867-667-8133 Tel * 867-393-7003 Fax
http://environmentyukon.gov.yk.ca/geomatics/
--------------------------------------------
_______________________________________________
gdal-dev mailing list
gdal-dev at lists.osgeo.org
http://lists.osgeo.org/mailman/listinfo/gdal-dev


Sent via BlackBerry by AT&T