[GRASS-user] Re: r.stream.extract Syntax Problem [UPDATE]

[Rich Shepard]

On Fri, 6 Apr 2012, Helmut Kudrnovsky wrote:

> - is the elevation exactly the same map used to calculate accumulation?

Helmut,

   I re-ran each step and saw the same error when r.stream.extract uses the
weighted accumulation map.

   r.info map=dem10m.avg:

Type of Map:  raster               Number of Categories: 255             |
    Data Type:    DCELL
    Rows:         2671
    Columns:      3216
    Total Cells:  8589936
         Projection: Lambert Conformal Conic
             N:     735780    S:     655650   Res:    30
             E:    2138580    W:    2042100   Res:    30
    Range of data:    min = 561.412536621094  max = 2212.32543945312

   r.info map=dem10m.acc.weighted:

Type of Map:  raster               Number of Categories: 255             |
    Data Type:    DCELL
    Rows:         2671
    Columns:      3216
    Total Cells:  8589936
         Projection: Lambert Conformal Conic
             N:     735780    S:     655650   Res:    30
             E:    2138580    W:    2042100   Res:    30
    Range of data:    min = -60301.3530574744  max = 3455.01235646488

   The error is: Accumulation map does not match elevation map! Could the
range of elevation data be the issue? The weighting formula multiplies
tangential curve values < 0 by -100 * tangential curve values.

Rich