<div dir="ltr">Hi Micha,<br><br>No worries, thanks for the headsup re: creating subsets. I noticed that resolution thing also, and just thought that it was because that scene is from a different path/row and the g.region command actually sets the region on the edge of this scene, so there are null values from this scene in the processing region. I have since gotten rid of this scene, but I figure that might explain it?<br><br>JDC</div><div class="gmail_extra"><br><div class="gmail_quote">On Tue, May 12, 2015 at 1:52 PM, Micha Silver <span dir="ltr"><<a href="mailto:micha@arava.co.il" target="_blank">micha@arava.co.il</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div style="direction:ltr" bgcolor="#FFFFFF" text="#000000">
Hi Jake<br>
Excuse for butting in...<span class=""><br>
<br>
<div>On 05/12/2015 05:23 PM, Jake Chila
wrote:<br>
</div>
<blockquote type="cite">
<div dir="ltr">Hi Moritz,<br>
<br>
I definitely did mean 'g.region -p', sorry for that. I ended up
getting it to work using 'r.mapcalc' after setting the region. I
saw someone online had used it with the simple expression
newmap=oldmap. Then, when I export the newmap it is only of the
subset. This small workaround was easy to set up, but I don't
have any idea why it didn't work in the first place. <br>
<br>
</div>
</blockquote>
<br></span>
It's not a "workaround". The correct way to clip a section of a
raster is two steps: define the new region with g.region, then run
r.mapcalc (which honors the region settings) to get a new raster, at
the new region settings, with values equal to the original.<br>
<br>
However, in your <a href="http://r.info" target="_blank">r.info</a> output below, something seems wrong with the
resolution. The landsat imagery is at 30 meters resolution. WHere
did the (very small) values below come from? And why is the N-S 6
times smaller than the E-W ??<div><div class="h5"><br>
<br>
<blockquote type="cite">
<div dir="ltr"><a href="http://r.info" target="_blank">r.info</a>
returns:
<div><br>
<div>(Tue May 12 11:19:01 2015)
</div>
<div><a href="http://r.info" target="_blank">r.info</a>
map=L5_2007_ATCOR_COMP@Jacob
</div>
<div> +----------------------------------------------------------------------------+</div>
<div> | Map: L5_2007_ATCOR_COMP@Jacob Date: Mon May
04 14:31:43 2015 |</div>
<div> | Mapset: Jacob Login of
Creator: Jacob |</div>
<div> | Location: FordingRiver
|</div>
<div> | DataBase: C:\Users\Jacob\Documents\grassdata
|</div>
<div> | Title: ( L5_2007_ATCOR_COMP )
|</div>
<div> | Timestamp: none
|</div>
<div> |----------------------------------------------------------------------------|</div>
<div> |
|</div>
<div> | Type of Map: raster Number of
Categories: 0 |</div>
<div> | Data Type: CELL
|</div>
<div> | Rows: 11374
|</div>
<div> | Columns: 12191
|</div>
<div> | Total Cells: 138660434
|</div>
<div> | Projection: UTM (zone 11)
|</div>
<div> | N: 557000 S: 554300 Res:
0.23738351 |</div>
<div> | E: 659000 W: 642200 Res:
1.37806579 |</div>
<div> | Range of data: min = 0 max = 32767
|</div>
<div> |
|</div>
<div> | Data Description:
|</div>
<div> | generated by r.composite
|</div>
<div> |
|</div>
<div> | Comments:
|</div>
<div> | r.composite red="GRASS_ATCOR_2007_B3@Jacob"
green="GRASS_ATCOR_2007_\ |</div>
<div> | B2@Jacob" blue="GRASS_ATCOR_2007_B1@Jacob"
levels=32 output="L5_2007\ |</div>
<div> | _ATCOR_COMP"
|</div>
<div> |
|</div>
<div> +----------------------------------------------------------------------------+</div>
<div>(Tue May 12 11:19:02 2015) Command finished (0 sec)</div>
<br>
<br>
However, I have encountered a new problem. On one of my ETM+
images, the subset is returned as an empty raster. The process
runs fine on the other ETM+ image from one year earlier but
for some reason, the subset from the scene one year later has
a min and max data range of 'NULL'. This range appears to be
constant across all the other scenes, so is there a way for me
to quickly edit this scene so it has the correct data? <br>
<br>
</div>
</div>
</blockquote>
<br></div></div>
As before, I would double check "g.region -p", and "<a href="http://r.info" target="_blank">r.info</a>" for both
the original Landsat image, and the clipped image that comes out
NULL.<br>
<br>
<br>
<blockquote type="cite"><div><div class="h5">
<div dir="ltr">
<div>Thanks,<br>
<br>
JDC</div>
</div>
<div class="gmail_extra"><br>
<div class="gmail_quote">On Tue, May 12, 2015 at 3:33 AM, Moritz
Lennert <span dir="ltr"><<a href="mailto:mlennert@club.worldonline.be" target="_blank">mlennert@club.worldonline.be</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><span>On 08/05/15 19:13, Jake Chila wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Hey all,<br>
<br>
I am currently working with some landsat data in Grass
7.0.0 on windows<br>
7, and am trying to hone in on my study area (much
smaller than the<br>
whole scene). From what I can tell, the best way to do
this is through<br>
the 'g.region' command however, I am having significant
problems getting<br>
this module to run correctly.<br>
<br>
my input is:<br>
<br>
g.region n=5572425 s=5536865 e=655050 w=626350 res=30<br>
<br>
One thing is that it runs in '0 seconds' so I think that
is a little odd.<br>
</blockquote>
<br>
</span>
It's normal as the command just changes a few entries in a
text file, so it is really fast.<span><br>
<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<br>
When I use the 'g.region -d' command I can see that
everything is set<br>
properly,<br>
</blockquote>
<br>
</span>
Did you maybe mean g.region -p ? At least this is the
command you should use to check current region settings.<span><br>
<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
however when I update the map display nothing changes.
Also,<br>
when I export the file using 'r.out.gdal' it exports
nothing.<br>
<br>
<br>
('r.out.gdal -t -f --overwrite
input=LT5_2007_ATCORRCOMP@May_Project<br>
output=C:\Users\Jacob\Desktop\GRASS_Trials\exportattempt5
format=GTiff<br>
type=Uint16 nodata=0)<br>
</blockquote>
<br>
</span>
That should normally respect the region settings.<br>
<br>
What does<br>
<br>
<a href="http://r.info" target="_blank">r.info</a> LT5_2007_ATCORRCOMP<br>
<br>
give you ?<span><font color="#888888"><br>
<br>
Moritz<br>
</font></span></blockquote>
</div>
<br>
</div>
<br></div></div>
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</blockquote>
<br>
</div>
</blockquote></div><br></div>