[Gdal-dev] gdal_contour missing contours!

[Jeshua Lacock]

Hello,

This is almost certainly a user error, though I cannot figure it out.

I have a DEM (from NED imported to a new location with r.in.gdal -oe) 
in GRASS that reports that the min/max Z values are:

   min = 958.760071 max = 2162.167236

But when I export it to a TIFF (with r.out.tiff) and use the command:

  	gdal_contour -a elev mydem.tif my-countours -i 10.0

It successfully creates a shape file with levels going in increments of 
10 from 0 to 250. But there are many missing levels (below 0 and above 
250), for example see:
	<http://OpenOSX.com/missing-contours.png>

A sample TIFF of the DEM is here:

	http://OpenOSX.com/mydem.tif

How would I get gdal_contour to use the same values for the cells that 
GRASS uses (not 0-250, but the actual DEM elevation values)? Or short 
of that, how would I get it to draw all of the contours?

Any help is greatly appreciated.


Thanks,

Jeshua Lacock ___________________________
Programmer/Owner		Phone:	877.240.1364
http://OpenOSX.com		Fax:		415.462.6211
-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_