[Qgis-user] raster stats

[Tim Sutton]

Hi

On Mon, Nov 21, 2011 at 8:19 PM, John Callahan <john.callahan at udel.edu> wrote:
> I just downloaded the latest version of qgis-dev from OSGeo4W (1.9.90-Alpha
> rev. f0f8a12) and it works great.  Thank you Tim.  Wonderful.

These changes were backported to 1.7.1 and 1.7.2 as well so it should
work the same there too.

Regards

Tim

> - John
> ***********************************************
> John Callahan, Research Scientist
> Delaware Geological Survey, University of Delaware
> URL: http://www.dgs.udel.edu
> *************************************************
>
>
>
> On Sun, Nov 20, 2011 at 5:57 AM, Tim Sutton <lists at linfiniti.com> wrote:
>>
>> Hi
>>
>> On Sat, Nov 19, 2011 at 8:57 PM, John Callahan <john.callahan at udel.edu>
>> wrote:
>> > Does anyone has information on the progress of this ticket?  From
>> > reading
>> > the comments on the the ticket, it looks as though there are some
>> > possibilities for enhancement.
>> > I use rasters regularly so this issue comes quite often.  For one
>> > particular
>> > 10GB DEM (in IMG format) it takes 7 or 8 minutes to calculate stats in
>> > QGIS,
>> > which takes a while when it happens every time I open that file.  Stats
>> > have
>> > already been computed through gdalinfo.  Thanks for any information.
>> > - John
>> >
>>
>> This should no longer be an issue with recent changes I made. Please see:
>>
>> http://hub.qgis.org/issues/3735
>>
>> If you still get the issue, please let me know with detailed steps on
>> how to replicate.
>>
>> Thanks
>>
>> Tim
>>
>>
>> >
>> >
>> >
>> > On Thu, Apr 14, 2011 at 7:24 AM, Radim Blazek <radim.blazek at gmail.com>
>> > wrote:
>> >>
>> >> New ticket http://trac.osgeo.org/qgis/ticket/3735
>> >>
>> >> Radim
>> >>
>> >> On Mon, Mar 21, 2011 at 4:37 PM, John Callahan <john.callahan at udel.edu>
>> >> wrote:
>> >> > I'm not sure if this behavior is expected or I am missing something.
>> >> >
>> >> > I have a 1 band raster dataset (an elevation DEM) in TIF format.  It
>> >> > has
>> >> > statistics computed from "gdalinfo -stats mydata.tif"   However, when
>> >> > I
>> >> > open
>> >> > it in QGIS (both 1.6 and 1.7 trunk), and look at the Metadata tab in
>> >> > Layer
>> >> > properties, there are two sections that contain band stats
>> >> > information.
>> >> > The
>> >> > first section is labeled "Band 1" and lists the same stats as found
>> >> > using
>> >> > gdalinfo.  The second section is labeled "Band" and says "No stats
>> >> > collected
>> >> > yet" for band 1.  QGIS has to create the stats when I apply a color
>> >> > map
>> >> > or
>> >> > stretch.  For large rasters, this takes a while, and must be done
>> >> > each
>> >> > time
>> >> > it's used in QGIS.
>> >> >
>> >> > Has anyone experienced this behavior?  Is this expected?  Is there a
>> >> > way
>> >> > to
>> >> > let gdal compute all the stats that QGIS needs?  Thanks.
>> >> >
>> >> > - John
>> >> >
>> >> > **************************************************
>> >> > John Callahan, Research Scientist
>> >> > Delaware Geological Survey, University of Delaware
>> >> > URL: http://www.dgs.udel.edu
>> >> > **************************************************
>> >> >
>> >> > _______________________________________________
>> >> > Qgis-user mailing list
>> >> > Qgis-user at lists.osgeo.org
>> >> > http://lists.osgeo.org/mailman/listinfo/qgis-user
>> >> >
>> >> >
>> >
>> >
>> > _______________________________________________
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>> > Qgis-user at lists.osgeo.org
>> > http://lists.osgeo.org/mailman/listinfo/qgis-user
>> >
>> >
>>
>>
>>
>> --
>> Tim Sutton - QGIS Project Steering Committee Member (Release  Manager)
>> ==============================================
>> Please do not email me off-list with technical
>> support questions. Using the lists will gain
>> more exposure for your issues and the knowledge
>> surrounding your issue will be shared with all.
>>
>> Visit http://linfiniti.com to find out about:
>>  * QGIS programming and support services
>>  * Mapserver and PostGIS based hosting plans
>>  * FOSS Consulting Services
>> Skype: timlinux
>> Irc: timlinux on #qgis at freenode.net
>> ==============================================
>
>



-- 
Tim Sutton - QGIS Project Steering Committee Member (Release  Manager)
==============================================
Please do not email me off-list with technical
support questions. Using the lists will gain
more exposure for your issues and the knowledge
surrounding your issue will be shared with all.

Visit http://linfiniti.com to find out about:
 * QGIS programming and support services
 * Mapserver and PostGIS based hosting plans
 * FOSS Consulting Services
Skype: timlinux
Irc: timlinux on #qgis at freenode.net
==============================================