[GRASS-dev] difference between r.drain and r.path

Markus Metz markus.metz.giswork at gmail.com
Sun Jan 27 02:12:58 PST 2019


In GRASS 7.6+, r.drain = (r.fill.dir + )r.path, i.e. r.path and r.drain are
not the same.

Historically, r.drain has been cloned from r.fill.dir and enhanced to
extract paths following directions created with the method of r.fill.dir
which is included in r.drain. r.drain has been adjusted to also extract
paths following directions created by r.cost/r.walk.
In order to avoid code duplication between r.fill.dir and r.drain, and to
have a more generic path extraction module, r.path has been created and
r.drain transformed to a script calling r.fill.dir if needed. The
interfaces of r.drain and r.path are not identical, therefore r.drain has
been kept as a wrapper for r.fill.dir + r.path for backwards compatibility
with GRASS 7.4 and earlier.

Markus M

On Sat, Jan 26, 2019 at 6:32 AM Huidae Cho <grass4u at gmail.com> wrote:

> Hello,
>
> I had the same question before. These two modules are almost the same.
> Actually, r.drain is a wrapper for r.path and creates input directions
> internally, then just runs r.path. Not sure if it's worth keeping it just
> for that extra step.
>
> Best,
> Huidae
>
> On Thu, Jan 24, 2019 at 3:29 AM Moritz Lennert <
> mlennert at club.worldonline.be> wrote:
>
>> Hi,
>>
>> In GRASS 7.6 we have both r.drain and r.path. What is the difference
>> between the two ? Should r.drain be declared as deprecated and replaced
>> by r.path ?
>>
>> Moritz
>> _______________________________________________
>> grass-dev mailing list
>> grass-dev at lists.osgeo.org
>> https://lists.osgeo.org/mailman/listinfo/grass-dev
>
>
>
> --
> Huidae Cho, Ph.D., GISP, PE (MD), CFM, M.ASCE
> Open Source GIS Developer, GRASS GIS Development Team
> _______________________________________________
> grass-dev mailing list
> grass-dev at lists.osgeo.org
> https://lists.osgeo.org/mailman/listinfo/grass-dev
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/grass-dev/attachments/20190127/b8ac79e2/attachment.html>


More information about the grass-dev mailing list