[GRASS5] [bug #1372] (grass) r.mapcalc: strange multiplication bug

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this bug's URL: http://intevation.de/rt/webrt?serial_num=1372
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Hi,

while working with r.mapcalc (in fact r.mapcalc new version)
we came accross a strange multiplication error:

The idea was to multiply all values in
plancS11.30m at Curvature
with 100000. The result seems to be nonsense.


On Thu, Oct 24, 2002 at 05:43:25PM +0200, Steno Fontanari wrote:
 baez:insubri 171%r.info plancS11.30m at Curvature
 +----------------------------------------------------------------------------+
 | Layer:    plancS11.30m                   Date: Wed Jan 30 16:58:19 2002    |
 |   Type of Map:  raster              Number of Categories: 255              |
[...]
 |   Data Type:    DCELL                                                      |
 |   Rows:         3251                                                       |
 |   Columns:      3871                                                       |
 |   Total Cells:  12584621                                                   |
 |        Projection: Transverse Mercator (zone 0)                            |
 |            N:    5157109    S:    5059581   Res: 29.9993848                |
 |            E:    1728648    W:    1612512   Res: 30.00154999               |
 |   Range of data:    min =  -466153.648586 max = 466153.648586              |
 |                                                                            |
 |   Data Source:                                                             |
 |                                                                            |
 |   Data Description:                                                        |
 |    generated by r.param.scale                                              |
 +----------------------------------------------------------------------------+

baez:insubri 172%r.mapcalc 'pippo2=int(plancS11.30m at Curvature*100000)'
baez:insubri 172%r.support -r pippo2

  Updating the stats for [pippo2]

baez:insubri 173%r.info pippo2
 +----------------------------------------------------------------------------+
 | Layer:    pippo2                         Date: Thu Oct 24 17:26:50 2002    |
 | Mapset:   erdemolo                       Login of Creator: fontana         |
 | Location: pat                                                              |
 | DataBase: /mpa_gdata/ssi/BIO/GRASS_DATA/data                               |
 | Title:     ( pippo2 )                                                      |
 |----------------------------------------------------------------------------|
 |                                                                            |
 |   Type of Map:  raster              Number of Categories: 1082618906       |
 |   Data Type:    CELL                                                       |
 |   Rows:         3251                                                       |
 |   Columns:      3871                                                       |
 |   Total Cells:  12584621                                                   |
 |        Projection: Transverse Mercator (zone 0)                            |
 |            N:    5157109    S:    5059581   Res: 29.9993848                |
 |            E:    1728648    W:    1612512   Res: 30.00154999               |
 |   Range of data:    min =  -1082618906 max = 1082618906                    |
 |                                                                            |
 |   Data Source:                                                             |
 |   Data Description:                                                        |
 |    generated by r.mapcalc                                                  |
 |                                                                            |
 +----------------------------------------------------------------------------+


Did we hit an upper/lower limit of CELL?
If so, r.mapcalc should refuse to write an output map.


Markus


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Date: Thu, 24 Oct 2002 17:49:15 +0200
From: Markus Neteler <neteler at itc.it>
To: grass-bugs at intevation.de, Steno Fontanari <fontana at itc.it>
Subject: r.mapcalc: strange multiplication bug
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