Lat/lon compatibility for r.water.outlet

[awickert]

Adding the attached line to r.water.outlet allows it to work across the 180 meridian in lat/lon coordinate systems.

I believe that the GRASS command G_adjust_east_longitude() is flagged to work only in lat/lon coordinate systems, so there should not be backwards-compatibility issues, but I haven't tested it with a projected coordinate system.

It might be good as well to change to documentation to reflect that the Northing and Easting can also be Latitude and Longitude.

[awickert]

Extra line in main.c to solve longitude wraparound problem when building draiange basins with r.water.outlet

[awickert]

Just got an email from someone else having problems with this, so I increased the priority and the affected OS (it should be a totally cross-platform problem since it is a computational issue). This is really just an issue of copying and pasting one line of code, so it should be a simple fix.

[neteler]

Probably the added function needs to be encapsulated into a LatLong test?

​http://grass.osgeo.org/programming6/window__map_8c_source.html#l00149

[awickert]

Yes - looks like you are correct and that I misread when I used G_adjust_east_longitude and thought it performed the check; I really wanted G_adjust_easting that wraps G_adjust_east_longitude in the lat/lon projection check.

Thanks for looking into this!

[mlennert]

Replying to awickert:

Yes - looks like you are correct and that I misread when I used G_adjust_east_longitude and thought it performed the check; I really wanted G_adjust_easting that wraps G_adjust_east_longitude in the lat/lon projection check.

Thanks for looking into this!

Any reasons for not applying the proposed patch (but using G_adjust_easting instead of G_adjust_east_longitude) ?

Moritz

[awickert]

Replying to mlennert:

Replying to awickert:

Yes - looks like you are correct and that I misread when I used G_adjust_east_longitude and thought it performed the check; I really wanted G_adjust_easting that wraps G_adjust_east_longitude in the lat/lon projection check.

Thanks for looking into this!

Any reasons for not applying the proposed patch (but using G_adjust_easting instead of G_adjust_east_longitude) ?

Moritz

In my case, I'm not a GRASS-dev, so write access was what prevented me from doing this! I have now downloaded GRASS 6.4.5svn to incorporate all updates to date and have applied and checked this change. I am now working to incorporate it into GRASS 7.1.0svn and will open a separate ticket on that once I have finished.

Thanks in advance to whomever looks into (and hopefully accepts!) this fix. Files attached.

Andy Wickert

[awickert]

r.water.outlet main from 6.4.5svn

[awickert]

diffs from 9 OCT 2014

[martinl]

Ticket retargeted after milestone closed