Re: [gdal-dev] OSGB36 to WGS84 transformation

2013-01-09 Thread Hermann Peifer
On 2013-01-09 16:13, Johnny wrote: Are you aware of any way to batch process this in Linux to enable swift conversion of multiple references? You'd need a script that maps the 2-letter grid cell identifiers to the respective offsets, then calculates the Easting and Northing values. I can se

Re: [gdal-dev] OSGB36 to WGS84 transformation

2013-01-09 Thread Johnny
Thanks Hermann, Hermann Peifer writes: > The lower left corner coordinates of the SD square are: > 300 000 metres East > 400 000 metres North > > So your test coordinate is at (Easting Northing): 380150 402109 > > echo "380150 402109" | gdaltransform -s_srs EPSG:27700 -t_srs EPSG:4326 > -2.3008

Re: [gdal-dev] OSGB36 to WGS84 transformation

2013-01-09 Thread Johnny
Jukka Rahkonen writes: > Johnny gmx.co.uk> writes: >> >> I am trying to convert OSGB grid references to WGS84, but do not succeed >> and don't understand why? > > Conclusion: gdaltransform does not understand OSGB grid references. What made > you to believe it would? I could not find anything

Re: [gdal-dev] substitute pixel values

2013-01-09 Thread Brian Case
hey Michael i have done this with a vrt. you can use a The ComplexSource supports adding a custom lookup table to transform the source values to the destination. The LUT can be specified using the following form: [src value 1]:[dest value 1],[src value 2]:[dest value 2],... http://www.gd

Re: [gdal-dev] substitute pixel values

2013-01-09 Thread Hare, Trent
Micheal, Check out repl_val.py in the GDAL/python samples. http://svn.osgeo.org/gdal/trunk/gdal/swig/python/samples/ Changing it slightly you can do what you want. original replace single value: scanline = numpy.choose( numpy.equal( scanline, inNoData),

Re: [gdal-dev] substitute pixel values

2013-01-09 Thread Joaquim Luis
Sorry to come out so often with GMT solutions in this GDAL list but somethings are so trivial there. If you can trust that all your negative values are (mean)seawater, this will do the job grdclip yourGrid -Sb0/0 -Gclipped_grid.nc Note, one need the dev

Re: [gdal-dev] substitute pixel values

2013-01-09 Thread Travis Kirstine
Michael, I'm not sure if you can do this using one of the existing utilities, you may be able to do this my creating a virtual file (gdalbuildvrt) and modifying it see - http://www.gdal.org/gdal_vrttut.html, but I have not attempted this. An alternative is to do this using the API and something l

Re: [gdal-dev] substitute pixel values

2013-01-09 Thread Ivan Lucena
Hi Michael, It seems like it would be better to mask out with a Land/Sea image 'cause you don't want to loose part of your shore that might be lower then the waves. Well, I might be wrong. I haven't been at the beach for a long time :) Regards, Ivan ---Original Message--- From: Smit

[gdal-dev] substitute pixel values

2013-01-09 Thread Smith, Michael
I have some DEMs that are created from lidar. For reasons related to seeing currents and wind effect, we did not ask for the water to be flattened, but rather it shows waves. This is cool, and what we wanted. BUT of course now we want to create a second set of DEMs with a nice flat ocean. I

Re: [gdal-dev] OSGB36 to WGS84 transformation

2013-01-09 Thread Hermann Peifer
The lower left corner coordinates of the SD square are: 300 000 metres East 400 000 metres North So your test coordinate is at (Easting Northing): 380150 402109 echo "380150 402109" | gdaltransform -s_srs EPSG:27700 -t_srs EPSG:4326 -2.30083027968938 53.5152719980087 48.8662291513756 Please no

[gdal-dev] Identifying a line for dangle

2013-01-09 Thread SIVA RAMA KRISHNA
hai to All, I am Trying to check for a line (OGRLINESTRING) to be a dangle or not. I am trying it out by checking each feature with remaining feature where any other feature(OGRLINESTRING) crosses its any of the node i am attaching a file any help is greatly appreciated With Regards Danglet

Re: [gdal-dev] OSGB36 to WGS84 transformation

2013-01-09 Thread Jukka Rahkonen
Johnny gmx.co.uk> writes: > > Hi, > > I am trying to convert OSGB grid references to WGS84, but do not succeed > and don't understand why? > > I use > > : echo "SD8015002109 "|gdaltransform -s_srs EPSG:27700 -t_srs EPSG:4326 > > which gives > > : -7.55729138544866 49.7667307394399 50.480