[GRASS-user] r.mapcalc appears to have changed behavior

[Jim Mochel]

Thank you. !

I am not sure how I did that but I am sure it seemed like a good idea at the
time :-)

Jim

On Tue, Sep 27, 2011 at 1:02 AM, Michael Barton <michael.barton at asu.edu>wrote:

> It looks like for the 2nd calculation, your computational region is set to
> extents of 0W - 1E, 0S - 1N, with a resolution of 1.
>
> So r.mapcalc is only operating on a single 1x1 cell that is outside the
> area of your raster map.
>
> Michael
> ____________________
> C. Michael Barton
> Director, Center for Social Dynamics & Complexity
> Professor of Anthropology, School of Human Evolution & Social Change
> Arizona State University
>
> voice:  480-965-6262 (SHESC), 480-727-9746 (CSDC)
> fax:          480-965-7671 (SHESC),  480-727-0709 (CSDC)
> www: http://www.public.asu.edu/~cmbarton, http://csdc.asu.edu
>
>
>
>
>
>
>
>
>
>
>
> On Sep 27, 2011, at 11:50 PM, <grass-user-request at lists.osgeo.org> <
> grass-user-request at lists.osgeo.org> wrote:
>
> > Date: Mon, 26 Sep 2011 23:19:11 -0400
> > From: Jim Mochel <jim.mochel.hivol at gmail.com>
> > Subject: [GRASS-user] r.mapcalc appears to have changed behavior
> > To: grass-user at lists.osgeo.org
> > Message-ID:
> >        <CAE=Y9-Q7tFZ=cJ4TC6nceYA5B=
> R9E7RRwZbVfF_fYbMNTEpC6A at mail.gmail.com>
> > Content-Type: text/plain; charset="iso-8859-1"
> >
> > I had made a number of scripts that worked fine in the 6.4.0 build 6 but
> > appear to have problems with the same code in later revisions:
> >
> > The method used to take about 6-8 secs and produce about what you would
> > expect on the screen. Now the same calculation takes 0 seconds the file
> is
> > radically changed. See the before and after below.
> >
> > Any help would be greatly appreciated.
> > Thanks
> > Jim Mochel
> >
> > r.mapcalc na_dem_sub_20 = na_dem_input - 20
> >
> >
> >
> +----------------------------------------------------------------------------+
> > | Layer:    na_dem                         Date: Sat Sep 24 17:37:59 2011
> > |
> > | Mapset:   PERMANENT                      Login of Creator: jmochel
> >  |
> > | Location: wgs84
> > |
> > | DataBase: /home/jmochel/grassdata
> > |
> > | Title:     ( na_dem )
> > |
> > | Timestamp: none
> > |
> >
> |----------------------------------------------------------------------------|
> > |
> > |
> > |   Type of Map:  raster               Number of Categories: 65535
> >  |
> > |   Data Type:    CELL
> >  |
> > |   Rows:         8384
> >  |
> > |   Columns:      9102
> >  |
> > |   Total Cells:  76311168
> >  |
> > |        Projection: x,y
> >  |
> > |            N:    4384500    S:   -3999500   Res:  1000
> >  |
> > |            E:    4639500    W:   -4462500   Res:  1000
> >  |
> > |   Range of data:    min = 0  max = 65535
> >  |
> > |
> > |
> > |   Data Description:
> > |
> > |    generated by r.in.gdal
> > |
> > |
> > |
> > |   Comments:
> > |
> > |    r.in.gdal input="/home/jmochel/gis/raw-data/hydo1k/na_dem.bil"
> outpu\
> >  |
> > |    t="na_dem"
> > |
> > |
> > |
> >
> +----------------------------------------------------------------------------+
> >
> >
> > r.info map=na_dem_sub_20
> >
> >
> +----------------------------------------------------------------------------+
> > | Layer:    na_dem_sub_20                  Date: Mon Sep 26 23:06:03 2011
> > |
> > | Mapset:   PERMANENT                      Login of Creator: jmochel
> >  |
> > | Location: wgs84
> > |
> > | DataBase: /home/jmochel/grassdata
> > |
> > | Title:     ( na_dem_sub_20 )
> >  |
> > | Timestamp: none
> > |
> >
> |----------------------------------------------------------------------------|
> > |
> > |
> > |   Type of Map:  raster               Number of Categories: 610
> >  |
> > |   Data Type:    CELL
> >  |
> > |   Rows:         1
> > |
> > |   Columns:      1
> > |
> > |   Total Cells:  1
> > |
> > |        Projection: x,y
> >  |
> > |            N:          1    S:          0   Res:     1
> >  |
> > |            E:          1    W:          0   Res:     1
> >  |
> > |   Range of data:    min = 610  max = 610
> >  |
> > |
> > |
> > |   Data Description:
> > |
> > |    generated by r.mapcalc
> > |
> > |
> > |
> > |   Comments:
> > |
> > |    na_dem_input at PERMANENT - 20
> >  |
> > |
> > |
> >
> +----------------------------------------------------------------------------+
>
>
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