[GRASS-user] Re: grass-user Digest, Vol 47, Issue 52
Micha Silver
micha at arava.co.il
Mon Mar 29 04:58:54 EDT 2010
Nathaniel:
Nathaniel Iwuchukwu wrote:
> Please what's the procedure or commands for extrating road network
> from a raster map? i think i have been going round the circle with
> classofocation and rectification of image. i have used this commands
Hope you didn't mean "class-suffocation" ;-)
> but i don't get any results:
> i.group
> i.composite
> i.class
> i.cluster
> r.digit
> i.maxlik
> i.gensigset
> nothing seems to get me the road network result i want.
What kind of raster are we talking about? If this is a scanned topo map,
with the roads symbolized by a certain color, then you might be able to
get started with a simple r.mapcalc. First identify the exact value of
the pixels of the road, then something like:
r.mapcalc road_rast="if( raster_map=<road_pixel_value>, 1, null() )
then do:
r.thin road_rast out=road_rast_thin
r.to.vect road_rast_thin type=line out=road_vect
Note: this won't get you a road "network", just a line vector. Creating
a proper network is another process.
Note 2: If you're working with an aerial photo, then the above won't do
you any good. In that case you will have to try some procedure of image
classification. And then you'll have to deal with the problem you
mentioned previously of running out of memory... Either more RAM in the
computer, or a smaller region, or a larger resolution.
> Please i need help and i am running GRASS on Linux Ubuntu.
> thanks.
>
> On Mon, Mar 22, 2010 at 11:09 AM, <grass-user-request at lists.osgeo.org
> <mailto:grass-user-request at lists.osgeo.org>> wrote:
>
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> Today's Topics:
>
> 1. ERROR: G_malloc: unable to allocate 2147483648 bytes at
> main.c:153 (ikechinedu at gmail.com <mailto:ikechinedu at gmail.com>)
> 2. Re: importing dem files: projection details? (Markus Neteler)
> 3. Re: ERROR: G_malloc: unable to allocate 2147483648 bytes at
> main.c:153 (Hamish)
> 4. Re: make command (install add on) (schorschli)
> 5. Helpp needed to call Grass from inside Python Plugin
> (Bishwarup Banerjee)
> 6. grass editing (Gary Nobles)
> 7. Re: ERROR: G_malloc: unable to allocate 2147483648 bytes at
> main.c:153 (Glynn Clements)
> 8. Osgeo4W grass error (Pablo Carreira)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Sun, 21 Mar 2010 13:02:00 -0700
> From: ikechinedu at gmail.com <mailto:ikechinedu at gmail.com>
> Subject: [GRASS-user] ERROR: G_malloc: unable to allocate 2147483648
> bytes at main.c:153
> To: grass-user at lists.osgeo.org <mailto:grass-user at lists.osgeo.org>
> Message-ID:
> <4529578.106556.1269201720004.JavaMail.root at jim.nabble.com
> <mailto:4529578.106556.1269201720004.JavaMail.root at jim.nabble.com>>
> Content-Type: text/plain; charset=us-ascii
>
> Hi, i am trying extract road network from a raster map but each
> time i run the image filter, i get this error message: ERROR:
> G_malloc: unable to allocate 2147483648 bytes at main.c:153.
>
> i also connnot use the i.class command on my windows machine which
> is the platform i am working with. please how can i extract a road
> network from raster map on windows platform?
> thank you.
> Nathaniel
>
>
> ------------------------------
>
> Message: 2
> Date: Mon, 22 Mar 2010 00:23:48 +0100
> From: Markus Neteler <neteler at osgeo.org <mailto:neteler at osgeo.org>>
> Subject: Re: [GRASS-user] importing dem files: projection details?
> To: Tyler Smith <tyler.smith at eku.edu <mailto:tyler.smith at eku.edu>>
> Cc: GRASS user list <grass-user at lists.osgeo.org
> <mailto:grass-user at lists.osgeo.org>>
> Message-ID:
> <86782b611003211623x6f777673t62a66fff6526f2d at mail.gmail.com
> <mailto:86782b611003211623x6f777673t62a66fff6526f2d at mail.gmail.com>>
> Content-Type: text/plain; charset=ISO-8859-1
>
> On Mon, Mar 15, 2010 at 7:38 PM, Tyler Smith <tyler.smith at eku.edu
> <mailto:tyler.smith at eku.edu>> wrote:
> > On 03/15/2010 09:38 AM, Markus Neteler wrote:
> >> On Mon, Mar 15, 2010 at 1:35 PM, Tyler
> Smith<tyler.smith at eku.edu <mailto:tyler.smith at eku.edu>> wrote:
> >>> On 03/15/2010 03:42 AM, Markus Neteler wrote:
> >>>
> >>> Trying the auto route:
> >>>
> >>> grass64 -gui
> >>> select define new location with georeferenced file
> >>> select the dem file: k42.dem
> >>> select the TN transformation, as probably better than the
> default for
> >>> adjacent Kentucky
> >>> enter GRASS with the newly created location and the PERMANENT
> mapset
> >>>
> >>> Results in this error:
> >>>
> >>> "g.proj or projection error: ERROR: default region is invalid
> >>> line 3:<north: 1080:43:46N>"
> >>>
> >>> So GRASS has automatically set up the location using degrees,
> and then
> >>> get
> >>> confused when the raster co-ordinates are provided in meters.
> Which
> >>> appears
> >>> to be fairly close to the sort of problem I ran into when
> setting this up
> >>> manually. What am I missing?
> >>>
> >>
> >> Please post the output of gdalinfo on that file. GRASS uses
> GDAL to detect
> >> projections from metadata.
> >>
> >> Markus
> >>
> >
> > Thanks for help! Here it is:
> >
> > gdalinfo k42.dem
> > Driver: USGSDEM/USGS Optional ASCII DEM (and CDED)
> > Files: k42.dem
> > Size is 1222, 1535
> > Coordinate System is:
> > GEOGCS["NAD83",
> > DATUM["North_American_Datum_1983",
> > SPHEROID["GRS 1980",6378137,298.257222101,
> ...
> > Metadata:
> > AREA_OR_POINT=Point
> > Corner Coordinates:
> >
> > Upper Left ( 1467.054, 1080.729)
> > Lower Left ( 1467.054, 1067.938)
> > Upper Right ( 1477.237, 1080.729)
> > Lower Right ( 1477.237, 1067.938)
> > Center ( 1472.146, 1074.334)
> ...
>
> I get actually a somewhat different result (GDAL trunk):
>
> gdalinfo m40.dem
> Driver: USGSDEM/USGS Optional ASCII DEM (and CDED)
> Files: m40.dem
> ...
> Corner Coordinates:
> Upper Left ( 1447.317, 1055.177) (Invalid angle,Invalid angle)
> Lower Left ( 1447.317, 1042.411) (Invalid angle,Invalid angle)
> Upper Right ( 1457.509, 1055.177) (Invalid angle,Invalid angle)
> Lower Right ( 1457.509, 1042.411) (Invalid angle,Invalid angle)
> Center ( 1452.413, 1048.794) (Invalid angle,Invalid angle)
> Band 1 Block=1223x1532 Type=Float32, ColorInterp=Undefined
> NoData Value=-32767
> Unit Type: ft
>
> You may want to signal this as GDAL bug in the GDAL butracker:
> http://trac.osgeo.org/gdal/
>
> Unless GDAL doesn't read it correctly, it won't be understood by
> GRASS.
> I tested with
> ftp://ftp.kymartian.ky.gov/dems_usgs/m39.dem.zip
>
> Markus
>
>
> ------------------------------
>
> Message: 3
> Date: Sun, 21 Mar 2010 22:41:12 -0700 (PDT)
> From: Hamish <hamish_b at yahoo.com <mailto:hamish_b at yahoo.com>>
> Subject: Re: [GRASS-user] ERROR: G_malloc: unable to allocate
> 2147483648 bytes at main.c:153
> To: grass-user at lists.osgeo.org
> <mailto:grass-user at lists.osgeo.org>, ikechinedu at gmail.com
> <mailto:ikechinedu at gmail.com>
> Message-ID: <373432.58091.qm at web110015.mail.gq1.yahoo.com
> <mailto:373432.58091.qm at web110015.mail.gq1.yahoo.com>>
> Content-Type: text/plain; charset=us-ascii
>
> Nathaniel wrote:
> > Hi, i am trying extract road network
> > from a raster map but each time i run the image filter, i
> > get this error message: ERROR: G_malloc: unable to allocate
> > 2147483648 bytes at main.c:153.
>
> aka it is trying to use >2gig RAM and there is not enough memory.
> Possibly because you are not using a 64bit OS, and possibly because
> you don't actually have that much memory in your computer.
> Maybe try on a smaller dataset?
>
> > i also connnot use the i.class command on my windows
> > machine which is the platform i am working with.
>
> you will have to wait for someone to build GRASS 6.4.0RC6 for Cygwin.
> i.class uses UNIX-style Xmonitors which are not available on standard
> MS Windows. (or try GRASS on a Mac or Linux computer/virtual machine)
>
>
> Hamish
>
>
>
>
>
>
> ------------------------------
>
> Message: 4
> Date: Mon, 22 Mar 2010 01:44:01 -0800 (PST)
> From: schorschli <matthiasoswald at hotmail.com
> <mailto:matthiasoswald at hotmail.com>>
> Subject: [GRASS-user] Re: make command (install add on)
> To: grass-user at lists.osgeo.org <mailto:grass-user at lists.osgeo.org>
> Message-ID: <1269251041185-4776893.post at n2.nabble.com
> <mailto:1269251041185-4776893.post at n2.nabble.com>>
> Content-Type: text/plain; charset=us-ascii
>
>
> Thanks for answering.
>
>
> >Are you sure about this directory?
>
> >MODULE_TOPDIR should point to the GRASS installation directory which
> >contains bin/, lib/ and other GRASS stuff.
>
>
> Yes, the directory is the one containing the grass-folders (bin/,
> lib/ and
> others).
>
> I could solve this problem. It was not a wrong MODULE_TOPDIR path,
> but wrong
> extensions for the makefiles.
>
>
>
> Now I can run the make command. But this is resulting in hunderts
> of errors
> and warning. Here is a printscreen of the first couple of lignes
> in the
> console...
>
> http://n2.nabble.com/file/n4776893/errors.png
> http://n2.nabble.com/file/n4776893/errors.png errors.png
>
>
> So maybe its better to just give it up with the addons...
>
>
>
> --
> View this message in context:
> http://n2.nabble.com/make-command-install-add-on-tp4764072p4776893.html
> Sent from the Grass - Users mailing list archive at Nabble.com.
>
>
> ------------------------------
>
> Message: 5
> Date: Mon, 22 Mar 2010 17:58:42 +0530
> From: Bishwarup Banerjee <bishwarup.banerjee at gmail.com
> <mailto:bishwarup.banerjee at gmail.com>>
> Subject: [GRASS-user] Helpp needed to call Grass from inside Python
> Plugin
> To: GRASS developers list <grass-dev at lists.osgeo.org
> <mailto:grass-dev at lists.osgeo.org>>,
> grass-user at lists.osgeo.org <mailto:grass-user at lists.osgeo.org>
> Message-ID:
>
> <78e951a61003220528o10e648a6m2fbd3c878a2897a2 at mail.gmail.com
> <mailto:78e951a61003220528o10e648a6m2fbd3c878a2897a2 at mail.gmail.com>>
> Content-Type: text/plain; charset="iso-8859-1"
>
> Hi All,
>
> I want to call the grass functionalities from inside my python
> plugins, in
> QGIS
> For example: the Grass's raster to polygon script, with out going
> inside the
> grass plugin.
> Can I set the Grass Mapset, and location from inside my python plugin?
> Is this possible?
> my configurations are:
> QGIS 0.11, GRASS 6.3, python 2.5, Windows
>
> Thank you in advance
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> ------------------------------
>
> Message: 6
> Date: Mon, 22 Mar 2010 03:10:42 -0800 (PST)
> From: Gary Nobles <garynobles at yahoo.com <mailto:garynobles at yahoo.com>>
> Subject: [GRASS-user] grass editing
> To: grass-user at lists.osgeo.org <mailto:grass-user at lists.osgeo.org>
> Message-ID: <1269256242668-4777030.post at n2.nabble.com
> <mailto:1269256242668-4777030.post at n2.nabble.com>>
> Content-Type: text/plain; charset=us-ascii
>
>
> Hi, I have been editing a grass point dataset in qgis
> unfortunately I have
> just added 400 centroids rather than points! Is there anyway to
> delete just
> the centroids?
>
> Thanks
>
> Gary
> --
> View this message in context:
> http://n2.nabble.com/grass-editing-tp4777030p4777030.html
> Sent from the Grass - Users mailing list archive at Nabble.com.
>
>
> ------------------------------
>
> Message: 7
> Date: Mon, 22 Mar 2010 13:54:49 +0000
> From: Glynn Clements <glynn at gclements.plus.com
> <mailto:glynn at gclements.plus.com>>
> Subject: Re: [GRASS-user] ERROR: G_malloc: unable to allocate
> 2147483648 bytes at main.c:153
> To: Hamish <hamish_b at yahoo.com <mailto:hamish_b at yahoo.com>>
> Cc: grass-user at lists.osgeo.org
> <mailto:grass-user at lists.osgeo.org>, ikechinedu at gmail.com
> <mailto:ikechinedu at gmail.com>
> Message-ID: <19367.30377.130266.683319 at cerise.gclements.plus.com
> <mailto:19367.30377.130266.683319 at cerise.gclements.plus.com>>
> Content-Type: text/plain; charset=us-ascii
>
>
> Hamish wrote:
>
> > > Hi, i am trying extract road network
> > > from a raster map but each time i run the image filter, i
> > > get this error message: ERROR: G_malloc: unable to allocate
> > > 2147483648 bytes at main.c:153.
> >
> > aka it is trying to use >2gig RAM and there is not enough memory.
> > Possibly because you are not using a 64bit OS, and possibly because
> > you don't actually have that much memory in your computer.
> > Maybe try on a smaller dataset?
>
> 2147483648 is exactly 2GiB; I'm wondering if that's the actual size
> (e.g. 16384 x 16384 x 8bytes/cell) or an uninitialised variable (e.g.
> initialised to INT_MIN in the code and not updated).
>
> On Linux, it is possible to allocate 2GiB on a 32-bit system, provided
> that there's a contiguous block (in practice, this means that the
> stack size isn't "unlimited"). You don't need that much physical RAM,
> only swap (although performance may be unacceptable if you're relying
> upon swap; it depends upon the access pattern).
>
> "Desktop" versions of Windows normally only allow 2GiB on 32-bit
> systems. Server versions allow up to 3GiB, and the desktop versions
> can be tweaked to allow it (but it isn't straightforward).
>
> > > i also connnot use the i.class command on my windows
> > > machine which is the platform i am working with.
> >
> > you will have to wait for someone to build GRASS 6.4.0RC6 for
> Cygwin.
> > i.class uses UNIX-style Xmonitors which are not available on
> standard
> > MS Windows. (or try GRASS on a Mac or Linux computer/virtual
> machine)
>
> I'll probably be building RC6 for Cygwin some time today.
>
> --
> Glynn Clements <glynn at gclements.plus.com
> <mailto:glynn at gclements.plus.com>>
>
>
> ------------------------------
>
> Message: 8
> Date: Mon, 22 Mar 2010 12:03:01 -0300
> From: Pablo Carreira <pablotcarreira at hotmail.com
> <mailto:pablotcarreira at hotmail.com>>
> Subject: [GRASS-user] Osgeo4W grass error
> To: <grass-user at lists.osgeo.org <mailto:grass-user at lists.osgeo.org>>
> Message-ID: <SNT114-W54FC77CFFE5D19331A6E4BD6270 at phx.gbl>
> Content-Type: text/plain; charset="utf-8"
>
>
> Hi, I'am trying to start the latest osgeo4w grass on windows 7 but
> I get an error when I select the dataset. Is it about the
> language? How can I start grass in english and not in portuguese?
>
> Regards,
> Pablo.
>
>
> Here is the error:
>
>
> C:\>"C:\OSGeo4W\apps\grass\grass-6.4.0svn"\etc\init.bat -wxpython
> access: Invalid argument
> ERRO:LOCAÃ├O << C:\teste/<UNKNOWN> >> indisponà vel
> Traceback (most recent call last):
> File
> "C:/OSGeo4W/apps/grass/grass-6.4.0svn/etc/wxpython/gis_set.py",
> line 853,
> in <module>
> GRASSStartUp = StartUp(0)
> File
> "C:\OSGeo4W\apps\Python25\lib\site-packages\wx-2.8-msw-unicode\wx\_core.p
> y", line 7935, in __init__
> self._BootstrapApp()
> File
> "C:\OSGeo4W\apps\Python25\lib\site-packages\wx-2.8-msw-unicode\wx\_core.p
> y", line 7509, in _BootstrapApp
> return _core_.PyApp__BootstrapApp(*args, **kwargs)
> File
> "C:/OSGeo4W/apps/grass/grass-6.4.0svn/etc/wxpython/gis_set.py",
> line 824,
> in OnInit
> StartUp = GRASSStartup()
> File
> "C:/OSGeo4W/apps/grass/grass-6.4.0svn/etc/wxpython/gis_set.py",
> line 165,
> in __init__
> self._set_properties()
> File
> "C:/OSGeo4W/apps/grass/grass-6.4.0svn/etc/wxpython/gis_set.py",
> line 206,
> in _set_properties
> self.OnSetDatabase(None)
> File
> "C:/OSGeo4W/apps/grass/grass-6.4.0svn/etc/wxpython/gis_set.py",
> line 664,
> in OnSetDatabase
> self.OnSelectLocation(None)
> File
> "C:/OSGeo4W/apps/grass/grass-6.4.0svn/etc/wxpython/gis_set.py",
> line 616,
> in OnSelectLocation
> self.listOfLocations[self.lblocations.GetSelection()]))
> File
> "C:/OSGeo4W/apps/grass/grass-6.4.0svn/etc/wxpython/gis_set.py",
> line 584,
> in UpdateMapsets
> stderr=None)
> File
> "C:\OSGeo4W\apps\grass\grass-6.4.0svn\etc\wxpython\gui_modules\gcmd.py",
> line 356, in __init__
> _("Error: ") + self.GetError()))
> File
> "C:\OSGeo4W\apps\grass\grass-6.4.0svn\etc\wxpython\gui_modules\gcmd.py",
> line 449, in GetError
> return unicode(msg, "utf-8")
> UnicodeDecodeError: 'utf8' codec can't decode bytes in position
> 4-5: invalid dat
> a
>
>
>
>
>
>
>
>
>
>
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--
Micha Silver
Arava Development Co. +972-52-3665918
http://www.surfaces.co.il
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