Rich,<br><br><div class="gmail_quote">On Mon, Apr 9, 2012 at 10:33 PM, Rich Shepard <span dir="ltr"><<a href="mailto:rshepard@appl-ecosys.com">rshepard@appl-ecosys.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Running r.stream.extract and removing nulls from the accumulation map<br>
produces weighted and unweighted stream maps with no data:<br></blockquote><div><br></div><div>there would have been a misunderstanding. Probably null values have their origin in the "weight" map, so IMHO you should run r.null on "weight" map, and then multiply it for the accumulation map. </div>
<div>In addiction, I also would check the projection, look at the resolution of your map.. how do you set the resolution? It should be 30 according to elevation map. Maybe the resolution of "weight" map doesn't match with the accumulation (and the elevation) ?</div>
<div><br></div><div>HTH,</div><div>madi</div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<br>
<a href="http://r.info" target="_blank">r.info</a> dem.noweight.streams<br>
Title: ( dem.noweight.streams )<br>
Type of Map: raster Number of Categories: 0<br>
Data Type: CELL<br>
Rows: 1045<br>
Columns: 1457<br>
Total Cells: 1522565<br>
Projection: Transverse Mercator<br>
N: 28660140.36123598 S: 28628801.89941604 Res: 29.98895868<br>
E: 549219.21981511 W: 505505.97596796 Res: 30.00222639<br>
Range of data: min = NULL max = NULL<br>
Data Description:<br>
generated by r.stream.extract<br>
<br>
Comments:<br>
r.stream.extract elevation="dem_proj" accumulation="dem.weighted" th\<br>
reshold=1000 d8cut=infinity mexp=0 stream_length=0 stream_rast="dem.\<br>
noweight.streams"<br>
<br>
and<br>
<br>
<a href="http://r.info" target="_blank">r.info</a> dem.weighted.streams<br>
Title: ( dem.weighted.streams )<br>
Type of Map: raster Number of Categories: 0<br>
Data Type: CELL<br>
Rows: 1045<br>
Columns: 1457<br>
Total Cells: 1522565<br>
Projection: Transverse Mercator<br>
N: 28660140.36123598 S: 28628801.89941604 Res: 98895868<br>
E: 549219.21981511 W: 505505.97596796 Res: 30.00222639<br>
Range of data: min = NULL max = NULL<br>
Data Description:<br>
generated by r.stream.extract<br>
Comments:<br>
r.stream.extract elevation="dem_proj" accumulation="dem.weighted" th\<br>
reshold=1000 d8cut=infinity mexp=0 stream_length=0 stream_rast="dem.\<br>
weighted.streams"<br>
<br>
What might I have done incorrectly now? Again, each step followed the<br>
r.stream.extract example with the addition of running r.null on the<br>
accumulation map.<br>
<br>
Rich<br>
<br>
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</blockquote></div><br><br clear="all"><div><br></div>-- <br>Ing. Margherita Di Leo, Ph.D.<br>