<div>Dear Doug, </div>
<div> </div>
<div>Now I see... I made a slip during the calculation. Namely, I've used NCEP/NCAR reanalysis data to calculate relative topography, and to do that I've used the command: </div>
<div> </div>
<div>***************************</div>
<div>sdfopen <a href="http://nomad1.ncep.noaa.gov:9090/dods/_expr_{reanalyses/reanalysis-1/6hr/pgb/pgb}{hgtprs(lev=500)-hgtprs(lev=1000)}{0">http://nomad1.ncep.noaa.gov:9090/dods/_expr_{reanalyses/reanalysis-1/6hr/pgb/pgb}{hgtprs(lev=500)-hgtprs(lev=1000)}{0</a>:<font style="BACKGROUND-COLOR: #cc0000">360</font>,-90:90,1000:1000,00z1jan1961:00z1jan1991}</div>
<div>***************************</div>
<div>However, the longitude in the original file (on nomad server) goes only up to 357.5. BUT, even if I replace 360 with 357.5 in the above command I get the same result---WHY? </div>
<div>Dear Doug, since I have more than a month of work behind me and all of that work was done usung the above command (with lon=360) and the result is the same as it would be 357.5 instead of 360, but the difference is in writing the result in a file, is it possible to change something in the CTL file and to correct a mistake? You were right, if in the previous command is 357.5, than I am able to set lon from -30 to 60. Since eveything else is the same, except this ploting issue, please is it possible to correct that so that I don't have to do the same tremandeus work from the beginning? </div>
<div> </div>
<div>Regards,</div>
<div>Djordje</div>
<div><br><br> </div>
<div class="gmail_quote">2011/5/9 Clark, Douglas B. <span dir="ltr"><<a href="mailto:dbcl@ceh.ac.uk">dbcl@ceh.ac.uk</a>></span><br>
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<p><span lang="EN">Djordje,</span></p>
<p><span lang="EN">I’m not sure, but I suspect that the problem might be related to the fact that the xdef entry in the ctl file appears to specify a grid that covers more than 360degrees of longitude, in that 145x2.5=362.5. So I think GrADS has failed to identify that the grid should be cyclic in longitude or just can’t work out which data to use in the “overlap” area. I certainly couldn’t get anything to plot across 0E when I hacked up an example, even when I tried a few standard “tricks”.</span></p>
<p><span lang="EN">(The fact that the grid is rather large in latitude too, >180deg, probably doesn’t matter because there’s no need for GrADS to wrap round in latitude. Also note that for a “basic” gridded data file, the t,z,y,x bit in the var line is not used, as far as I know – I tend to put “99” in there instead.)</span></p>
<p><span lang="EN">IF you only had one time level in the data file (which only has a single variable on a single level in it), you might be able to change the xdef line to have nx=144 so that GrADS thinks it only has data for 360deg – BUT THAT WILL NOT work for your current example which has >1 time.</span></p>
<p><span lang="EN">I think you’ll probably have to trim the grid to 360deg before going into GrADS if you want to plot across 0E.</span></p>
<p><span lang="EN">If the data file RTmavglobal(1961-1990).grd was written using fwrite to output a subset of a larger file, then I think you will be able to proceed by explicitly setting ‘set x 1 144’ before you write the file. Otherwise GrADS will likely have added an extra column of data because of how it normally sets up for a global grid.</span></p>
<p><span lang="EN">Doug</span></p>
<p class="MsoNormal"><span style="COLOR: #1f497d; FONT-SIZE: 11pt"> </span></p>
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<p class="MsoNormal"><b><span style="FONT-SIZE: 10pt" lang="EN-US">From:</span></b><span style="FONT-SIZE: 10pt" lang="EN-US"> <a href="mailto:gradsusr-bounces@gradsusr.org" target="_blank">gradsusr-bounces@gradsusr.org</a> [mailto:<a href="mailto:gradsusr-bounces@gradsusr.org" target="_blank">gradsusr-bounces@gradsusr.org</a>] <b>On Behalf Of </b>Djordje Romanic<br>
<b>Sent:</b> 09 May 2011 08:54<br><b>To:</b> GrADS Users Forum<br><b>Subject:</b> [gradsusr] LON-LAT for European sector</span></p></div>
<div>
<div></div>
<div class="h5">
<p class="MsoNormal"> </p>
<div>
<p class="MsoNormal">Dear Users,</p></div>
<div>
<p class="MsoNormal"> </p></div>
<div>
<p class="MsoNormal">I have a *.grd file (relative topography data) covering the whole globe. His CTL file is as follows: </p></div>
<div>
<p class="MsoNormal"> </p></div>
<div>
<p class="MsoNormal">***************************************************************************</p></div>
<div>
<p><span lang="EN">dset ^RTmavglobal(1961-1990).grd</span></p>
<p><span lang="EN">undef 9.999e+20</span></p>
<p><span lang="EN">xdef 145 linear 0 2.5</span></p>
<p><span lang="EN">ydef 73 linear -90 2.5</span></p>
<p><span lang="EN">zdef 1 levels 1000</span></p>
<p><span lang="EN">tdef 43709 linear 0Z31jan1961 360mn</span></p>
<p><span lang="EN">vars 1</span></p>
<p><span lang="EN">RT 1 t,z,y,x **Relative topography 500/1000 [hPa]</span></p>
<p><span lang="EN">endvars</span></p>
<p><span lang="EN">**************************************************************************</span></p>
<p><span lang="EN">The data on global map (LAT -90 90; LON 0 360) are attached (global.jpeg). Now, from the global file I want to extract the data for the European sector (longitude interval is from 30W to 60E and latitude interval is from 0 90N), but after the following commands: </span></p>
<p><span lang="EN">***********************************************************************</span></p>
<p><span lang="EN">set lon -30 60</span></p>
<p><span lang="EN">set lat 0 90</span></p>
<p><span lang="EN">d rt</span></p>
<p><span lang="EN">************************************************************************</span></p>
<p><span lang="EN">I get the image that does not have the data East of the 0 meridian(attached as file euro.jpeg). </span></p>
<p><span lang="EN">Please, can someone help me with this issue? What is causing this? </span></p>
<p><span lang="EN">Kind regards,</span></p>
<p><span lang="EN">Djordje</span></p></div></div></div></div><font color="#888888"><br>-- <br>This message (and any attachments) is for the recipient only. NERC <br>is subject to the Freedom of Information Act 2000 and the contents <br>
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