<div dir="auto">Okay, thanks for the clarification. <div dir="auto">(Also, I will remember to cc the list in future).<br><br>I have one more question if it's okay to ask(not related to above issue). I understand Grass GIS queries & issues are resolved through mailing lists at the moment and the archives. Not meaning to be disrespectful of the community, but won't it be much useful when we have a forum like website to post & answer each others queries (it can especially be useful since newcomers like me don't have to flood the mailing list with common issues)? </div><div dir="auto"><br></div><div dir="auto">Thank you.</div><div dir="auto"><br>Regards,</div><div dir="auto">Bharath Ram.</div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Tue, Nov 24, 2020, 3:30 AM Veronica Andreo <<a href="mailto:veroandreo@gmail.com" target="_blank" rel="noreferrer">veroandreo@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div>[cc-ing the list]</div><div><br></div><div>The examples in the manuals are in meters because they are based on the North Carolina sample dataset which CRS is Lambert Conformal Conic. The units of this CRS are meters. <br></div><div><br></div><div>g.proj -p<br>-PROJ_INFO-------------------------------------------------<br>name : Lambert Conformal Conic<br>proj : lcc<br>datum : nad83<br>a : 6378137.0<br>es : 0.006694380022900787<br>lat_1 : 36.16666666666666<br>lat_2 : 34.33333333333334<br>lat_0 : 33.75<br>lon_0 : -79<br>x_0 : 609601.22<br>y_0 : 0<br>no_defs : defined<br>-PROJ_UNITS------------------------------------------------<br>unit : Meter<br>units : Meters<br>meters : 1</div><div><br></div><div>You have to adjust to the units of the CRS that you use when it comes to resolution. There's no way to set resolution in meters if you work in latlong. Hence the recommendation to work in projected systems.</div><div><br></div><div> Some modules might use distance in meters for certain parameters even when working in latlong, because they convert such distances within the source code into radians (if I'm not mistaken). If not, they will raise a warning. Again, to avoid such issues, it's a good practice to work with projected CRS.<br></div><div><br></div><div>best, <br></div><div>Vero<br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">El lun, 23 nov 2020 a las 22:46, BHARATH RAM (<<a href="mailto:br11@iitbbs.ac.in" rel="noreferrer noreferrer" target="_blank">br11@iitbbs.ac.in</a>>) escribió:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="auto">Dear Ms.Veronica Andreo,<div dir="auto"> Thank you very much for your quick reply. Yes your suggestion works correctly. </div><div dir="auto"><br></div><div dir="auto">But I find it a litttle suprising since in the documentation (for modukes like r.resample.stats, r.sun etc..) & in several examples meter seems to be the default units used for distance and I assumed that for my case as well it was the same (even though g.region -p prints out in decimal degree).</div><div dir="auto"><br></div><div dir="auto">Is there any way to change the units back to meter as default?</div><div dir="auto"><br></div><div dir="auto">Thank you<br>Regards,<br><div dir="auto">Bharath</div></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Tue, Nov 24, 2020, 3:03 AM Veronica Andreo <<a href="mailto:veroandreo@gmail.com" rel="noreferrer noreferrer" target="_blank">veroandreo@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div>Hello Bharath, <br></div><div><br></div><div>I think your problem is that you are working in a latlong location and trying to set a resolution of 8000 degrees, which is not possible. If your desired final resolution is ~8 km, you will need to set the region resolution to its equivalent in degrees (the unit of latlong CRS). Otherwise, work with projected CRS like UTM for example (recommended).</div><div><br></div><div>Furthermore, if you want to go from high res to lower res (upscaling), r.resamp.stats is your friend, so the second approach would be fine. The problem lays in the resolution you are setting.</div><div><br></div><div>HTH, <br></div><div>Vero<br></div><div><br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">El lun, 23 nov 2020 a las 22:20, BHARATH RAM (<<a href="mailto:br11@iitbbs.ac.in" rel="noreferrer noreferrer noreferrer" target="_blank">br11@iitbbs.ac.in</a>>) escribió:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr">Hello everyone,<div><br></div><div> I am interested in performing resampling of a fine resolution DEM Model (which is imported as a GTiff file in grass GIS). I tried the following 2 approaches and neither of them was successful. Can you help me figure out where I went wrong? Thanks in Advance. </div><div><br></div><div><u>Details about originally imported DEM model:</u></div><div><i>projection: 3 (Latitude-Longitude)</i></div><i>zone: 0<br>datum: wgs84<br>ellipsoid: wgs84<br>north: 29N<br>south: 28:06N<br>west: 72E<br>east: 77:24E<br>nsres: 0:00:01.08<br>ewres: 0:00:01.08<br>rows: 3000<br>cols: 18000<br>cells: 54000000</i><div><u><br></u></div><div><u>MY AIM:</u> To convert a fine grid DEM (30 m resolution) to coarse grid DEM (8km)</div><div><br></div><div><u>APPROACH 1: Using <b>r.resample.rst</b></u></div><div><br></div><div><b>g.region raster=test5_r1</b></div><div><b>r.resamp.rst input=test5_r1 ew_res=8000 ns_res=8000 <u><br></u></b></div><div> In this second command's execution, I get error (log attached below):</div><div><i> Processing all selected output files will require </i><i>4 bytes of disk space for temp files.</i></div><i> Temporarily changing the region to desired resolution ...<br> Changing back to the original region ...<br> Percent complete:<br> ERROR: Unable to seek: Invalid argument</i><div> </div><div><u>APPROACH 2: Using <b>r.resample.stats</b></u> </div><div><b>g.region raster=test5_r1</b></div><div><b>g.region nsres=8000 ewres=8000 </b>// problematic part</div><div><b>r.resamp.stats -w input=test5_r1 output=test5_r1_8km</b></div><div><b> </b>In this second command's execution the entire map seems to get clubbed into a single large pixel. I have attached results of <b>g.region -ap</b> below:</div><div><i> projection: 3 (Latitude-Longitude)</i></div><i>
zone: 0<br>
datum: wgs84<br>
ellipsoid: wgs84<br>
north: 29N<br>
south: 28:06N<br>
west: 72E<br>
east: 77:24E<br>
nsres: 0:54<br>
ewres: 5:24<br>
rows: 1<br>
cols: 1<br>
cells: 1</i><div> <br></div><div><br></div><div>Also, can you tell me which method will be more suitable for my final goal?</div><div><br></div><div>Thanks & Regards,</div><div>Bharath</div><div><br></div><div><br></div><div><u><br></u></div></div>
<br>
<hr><font size="1" face="Verdana"><b>Disclaimer: </b>This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the system manager. This message contains confidential information and is intended only for the individual named. If you are not the named addressee you should not disseminate, distribute or copy this e-mail. Please notify the sender immediately by e-mail if you have received this e-mail by mistake and delete this e-mail from your system. If you are not the intended recipient you are notified that disclosing, copying, distributing or taking any action in reliance on the contents of this information is strictly prohibited.</font>_______________________________________________<br>
grass-user mailing list<br>
<a href="mailto:grass-user@lists.osgeo.org" rel="noreferrer noreferrer noreferrer" target="_blank">grass-user@lists.osgeo.org</a><br>
<a href="https://lists.osgeo.org/mailman/listinfo/grass-user" rel="noreferrer noreferrer noreferrer noreferrer" target="_blank">https://lists.osgeo.org/mailman/listinfo/grass-user</a><br>
</blockquote></div>
</blockquote></div>
<br>
<hr><font size="1" face="Verdana"><b>Disclaimer: </b>This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the system manager. This message contains confidential information and is intended only for the individual named. If you are not the named addressee you should not disseminate, distribute or copy this e-mail. Please notify the sender immediately by e-mail if you have received this e-mail by mistake and delete this e-mail from your system. If you are not the intended recipient you are notified that disclosing, copying, distributing or taking any action in reliance on the contents of this information is strictly prohibited.</font></blockquote></div>
</blockquote></div>
<br>
<hr><font face="Verdana" size="1"><b>Disclaimer: </b>This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the system manager. This message contains confidential information and is intended only for the individual named. If you are not the named addressee you should not disseminate, distribute or copy this e-mail. Please notify the sender immediately by e-mail if you have received this e-mail by mistake and delete this e-mail from your system. If you are not the intended recipient you are notified that disclosing, copying, distributing or taking any action in reliance on the contents of this information is strictly prohibited.</font>