[mapserver-users] a question re. gdallocationinfo

[Even Rouault]

Le jeudi 10 novembre 2011 19:55:52, Puneet Kishor a écrit :
> dunno if this is the right place to ask, but Frank W. hangs around here, so
> here goes...

Being a GDAL tool, this question would be better directed on gdal-dev mailing 
list.

> 
> I am quite enjoying querying some of my raster datasets via
> gdallocationinfo. Works quite well, which makes me want to do the
> following --
> 
> 1. Have gdallocationinfo be aware of the NODATA value in the data set so it
> returns something predictable such as "NO DATA" or "" or whatver.

No, gdallocationinfo only reports the numeric value. You can look at gdalinfo 
report to see if this value is no data or not

> 
> 2. Currently gdallocationinfo queries only a point. I would like it to
> query a polygon, and return summary info for the area... perhaps
> statistics, a histogram, and the like.

You could use "gdal_translate -of VRT src.tif extract.vrt -srcwin X Y Z W" for 
example to create a virtual dataset that is a subwindow of the total raster
and then "gdalinfo -stats -hist extract.vrt"

Even