<div dir="ltr">On Thu, Jul 10, 2014 at 5:40 AM, Anil Kumar <span dir="ltr"><<a href="mailto:anilku@oceanmanager.com" target="_blank">anilku@oceanmanager.com</a>></span> wrote:<br><div class="gmail_extra"><div class="gmail_quote">
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div lang="EN-US" link="blue" vlink="purple"><div><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Dear Arlindo,<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Thanks for your detailed reply. I have a few queries regarding the task I need to accomplish.<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p><p><u></u><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><span>1)<span style="font:7.0pt "Times New Roman""> </span></span></span><u></u><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">If Grads is not the best tool to accomplish my task, can you please suggest me the another tool, if you know, to accomplish the job ?<u></u><u></u></span></p>
<p><u></u><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><span></span></span></p></div></div></blockquote><div><br></div><div>Probably C or Fortran. You could also accomplish some of that with python with pygrads. All depends on how much programming experience you have.</div>
<div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div lang="EN-US" link="blue" vlink="purple"><div><p><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><span>2)<span style="font:7.0pt "Times New Roman""> </span></span></span><u></u><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Secondly, the approach which you have already shared with me as below<u></u><u></u></span></p>
<div class=""><p><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p><p>1) define a 2x2 global grid (say, use lterp with linear interpolation),<u></u><u></u></p>
<p>2) loop over every 2x2 region in the 0.25x0.5 deg grid, compute the 2 x2 area max with amax(), and use "set defval" to replace the corresponding value in the previous defined variable in 1). As I said, this is very inefficient.<u></u><u></u></p>
<p><u></u> <u></u></p></div><p class="MsoNormal" style="text-indent:.5in"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Should I need to create 2x2 global grid first physically first and then need to replace its values. If so, I don’t find any hint on google, <a href="http://gradsuser.org" target="_blank">gradsuser.org</a> to create a new grid. What is the procedure to create grid ?</span></p>
</div></div></blockquote><div><br></div><div><br></div><div>What I said was to define a 2x2 grid, for example</div><div><br></div><div>define u2x2 = re(u,2)</div><div><br></div><div> I really don't have the time to walk you thru the details as it would require me to actually write the code for you. If you can program in C or fortran I'd go that route. If you follow the UDF approach that I outlined you can still do grads for your plotting. And please do not write directly to me, I cannot afford to provide individualized grads support.</div>
<div><br></div><div> Good Luck,</div><div><br></div><div> Arlindo</div><div><br></div><div><br></div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div lang="EN-US" link="blue" vlink="purple"><div><p class="MsoNormal" style="text-indent:.5in"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u><u></u></span></p>
<p class="MsoNormal" style="text-indent:.5in"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p><p class="MsoNormal" style="text-indent:.5in"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Thanks again for your help.<u></u><u></u></span></p>
<div class=""><p><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#215868">Thanks & Regards<u></u><u></u></span></b></p><p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#215868">Anil Kumar <u></u><u></u></span></b></p>
</div><p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#00a1da">OceanManager</span></b><b><i><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#215868"> </span></i></b><b><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#00a1da">Inc.</span></b><b><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#009bd2"> </span></b><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:black">| </span><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><a href="http://www.oceanmanager.com/" target="_blank">www.oceanmanager.com</a></span><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#31849b"><u></u><u></u></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p><p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">From:</span></b><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""> <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>Arlindo da Silva<br>
<b>Sent:</b> Tuesday, July 01, 2014 7:12 AM<br><b>To:</b> GrADS Users Forum</span></p><div><div class="h5"><br><b>Subject:</b> Re: [gradsusr] Help on calculating Area Maximum from NetCDF file using Grads<u></u><u></u></div>
</div><p></p><div><div class="h5"><p class="MsoNormal"><u></u> <u></u></p><div><p class="MsoNormal">On Mon, Jun 30, 2014 at 9:37 AM, Anil Kumar <<a href="mailto:anilku@oceanmanager.com" target="_blank">anilku@oceanmanager.com</a>> wrote:<u></u><u></u></p>
<div><div><blockquote style="border:none;border-left:solid #cccccc 1.0pt;padding:0in 0in 0in 6.0pt;margin-left:4.8pt;margin-right:0in"><div><div><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Hi Grads users,</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">I am awaiting an useful comments or direction on the below case. Please lead me, to get all the maximum values from the small – small areas of every 2 degree in Lat and lon say for example. Below is my complete query.</span><u></u><u></u></p>
<div><div><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span><u></u><u></u></p><p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">My Requirement</span></b><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> : I have a larger dataset (.NC file) 1440*720 points. I want a new destination grid with linear interpolation having all the all area maximum values using amax() of small-small regions. And ultimately, need to query the destination grid for output.</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span><u></u><u></u></p></div></div></div></div></blockquote><div><p class="MsoNormal"><u></u> <u></u></p>
</div><div><p class="MsoNormal">I am afraid the regridding method you are looking for is not implemented by lterp() or re(). This is a good example of when GrADS is not the best tool for the job at hand. But if you insist, a very inefficient approach would be<u></u><u></u></p>
</div><div><p class="MsoNormal"><u></u> <u></u></p></div><div><p class="MsoNormal">1) define a 2x2 global grid (say, use lterp with linear interpolation),<u></u><u></u></p></div><div><p class="MsoNormal">2) loop over every 2x2 region in the 0.25x0.5 deg grid, compute the 2 x2 area max with amax(), and use "set defval" to replace the corresponding value in the previous defined variable in 1). As I said, this is very inefficient.<u></u><u></u></p>
</div><div><p class="MsoNormal"><u></u> <u></u></p></div><div><p class="MsoNormal">If you are up for some C/Fortran programming, you can use the opengrads IPC extension (which is available with your Windows build):<u></u><u></u></p>
</div><div><p class="MsoNormal"><u></u> <u></u></p></div><div><p class="MsoNormal"> <a href="http://opengrads.org/doc/udxt/libipc/" target="_blank">http://opengrads.org/doc/udxt/libipc/</a><u></u><u></u></p></div><div>
<p class="MsoNormal"><u></u> <u></u></p></div><div><p class="MsoNormal">to write your variables to disk,<u></u><u></u></p></div><div><p class="MsoNormal"><u></u> <u></u></p></div><div><p class="MsoNormal">ga-> ipc_save u_velocity u.bin<u></u><u></u></p>
</div><div><p class="MsoNormal">ga-> ipc_save v_velocity v.bin<u></u><u></u></p></div><div><p class="MsoNormal"><u></u> <u></u></p></div><div><p class="MsoNormal">Then write a C/Fortran program that read these files (u.bin,v.bin) and compute the amax at the 2x2 grid you require, writing output files (u2x2.bin.v2x2.bin). <u></u><u></u></p>
</div><div><p class="MsoNormal"><u></u> <u></u></p></div><div><p class="MsoNormal">ga-> ! my_amaxregrid <u></u><u></u></p></div><div><p class="MsoNormal"><u></u> <u></u></p></div><div><p class="MsoNormal">Consult the IPC documentation for the description of the transfer file format (very similar to the old GrADS 1.x UDF.) You can finally read these back with ipc_load() extension:<u></u><u></u></p>
</div><div><p class="MsoNormal"><u></u> <u></u></p></div><div><p class="MsoNormal">ga-> d ipc_load("u2x2.bin");ipc_load("v2x2.bin")<u></u><u></u></p></div><div><p class="MsoNormal"><u></u> <u></u></p>
</div><div><p class="MsoNormal">Notice that this is a poor-man version of the file-based UDF that existed in GrADS 1.x. Of course, you can accomplish the same more efficiently by writing a genuine OpenGrADS extension with no transfer files involved.<u></u><u></u></p>
</div><div><p class="MsoNormal"><u></u> <u></u></p></div><div><p class="MsoNormal"> Good Luck,<u></u><u></u></p></div><div><p class="MsoNormal"><u></u> <u></u></p></div><div><p class="MsoNormal"> Arlindo<u></u><u></u></p>
</div><div><p class="MsoNormal"><u></u> <u></u></p></div><div><p class="MsoNormal"><u></u> <u></u></p></div><div><p class="MsoNormal"><u></u> <u></u></p></div><div><p class="MsoNormal"> <u></u><u></u></p></div><blockquote style="border:none;border-left:solid #cccccc 1.0pt;padding:0in 0in 0in 6.0pt;margin-left:4.8pt;margin-right:0in">
<div><div><div><div><p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">What Am doing so far : </span></b><u></u><u></u></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">I have a NetCDF file having below CTL Info.</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">*****************************************************************</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">dset D:\WeatherGribFiles\2014\06\22\<a href="http://rtofs_glo_2ds_f024_daily_prog.nc" target="_blank">rtofs_glo_2ds_f024_daily_prog.nc</a></span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">title 2D Sfc Daily Prognostic 00Z22jun2014: Forecast, downloaded Jun 22 15:20 UTC</span><u></u><u></u></p><p class="MsoNormal">
<span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">undef 1.26765e+30</span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">dtype netcdf</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">xdef 1440 linear 74.16 0.24999</span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">ydef 720 linear -90 0.24999</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">zdef 1 linear 1 1</span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">tdef 1 linear 00Z23JUN2014 1mn</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">vars 2</span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">u_velocity=>u_velocity 1 t,z,y,x eastward_sea_water_velocity (m/s)</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">v_velocity=>v_velocity 1 t,z,y,x northward_sea_water_velocity (m/s)</span><u></u><u></u></p><p class="MsoNormal">
<span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">endvars</span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">*****************************************************************</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">I want a new destination grid ; which would contain the area maximum values as points. Destination grid should contain maximum value from every 8 points in x-axis and y axis. For this, I have created below, CTL file named as <b>rtofs_glo_2ds_f024_daily_prog.ctl</b>:</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">*****************************************************************</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">dset D:\WeatherGribFiles\2014\06\22\<a href="http://rtofs_glo_2ds_f024_daily_prog.nc" target="_blank">rtofs_glo_2ds_f024_daily_prog.nc</a></span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">index D:\WeatherGribFiles\2014\06\22\<span style="color:red">rtofs_glo_2ds_f024_daily_prog_DUMMY.nc </span></span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">title 2D Sfc Daily Prognostic 00Z22jun2014: Forecast, downloaded Jun 22 15:20 UTC </span><u></u><u></u></p><p class="MsoNormal">
<span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">undef 1.26765e+30 </span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">dtype netcdf </span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif";background:yellow">xdef 180 linear 74.16 2.0 </span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif";background:yellow">ydef 90 linear -90 2.0</span><span style="font-size:10.0pt;font-family:"Calibri","sans-serif""> </span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">zdef 1 linear 1 1 </span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">tdef 1 linear 00Z23JUN2014 1mn</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">options template </span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">vars 2 </span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">u_velocity=>u_velocity 1 t,z,y,x eastward_sea_water_velocity (m/s) </span><u></u><u></u></p><p class="MsoNormal">
<span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">v_velocity=>v_velocity 1 t,z,y,x northward_sea_water_velocity (m/s) </span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">endvars</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">*****************************************************************</span><u></u><u></u></p><p class="MsoNormal">
<span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Below is the command I use to display the data from destination grid <b>rtofs_glo_2ds_f024_daily_prog_DUMMY.nc </b>defined in above CTL file. Below is the command set using.</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">*****************************************************************</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">reinit</span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">sdfopen D:/WeatherGribFiles/2014/06/22/<a href="http://rtofs_glo_2ds_f024_daily_prog.nc" target="_blank">rtofs_glo_2ds_f024_daily_prog.nc</a></span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">open D:/WeatherGribFiles/2014/06/22/rtofs_glo_2ds_f024_daily_prog2.ctl</span><u></u><u></u></p><p class="MsoNormal">
<span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">set parea 0 11 0 8.5</span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">set vpage 0 11 0 8.5</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">set lon -74.16 434</span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">set lat -90 90</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">set cthick 6</span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">set arrscl 0.10 </span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">define val = mag(lterp(u_velocity.1*1.95,lat.2,amax),lterp(v_velocity.1*1.95,lat.2,amax))</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">d lterp(u_velocity.1*1.95,lat.2,amax);lterp(v_velocity.1*1.95,lat.2,amax);val</span><u></u><u></u></p><p class="MsoNormal">
<span style="font-size:10.0pt;font-family:"Calibri","sans-serif""> </span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">*****************************************************************</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">When I change the destination grid dimensions slightly in <b>rtofs_glo_2ds_f024_daily_prog.ctl </b>file</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif";background:yellow">xdef 135 linear 74.16 2.5 </span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif";background:yellow">ydef 68 linear -90 2.5</span><span style="font-size:10.0pt;font-family:"Calibri","sans-serif""> </span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">and checks for the output, It varies at the same point i.e. if I look at certain point before changing and after changing grid dimensions, the result comes of different magnitude.</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">What I want is, When I increase or decrease the destination grid points in “<b>rtofs_glo_2ds_f024_daily_prog.ctl”, </b>and the maximum value should be at its place. </span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">How can I achieve this ????? </span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span><u></u><u></u></p>
</div></div><div><p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#215868">Thanks & Regards</span></b><u></u><u></u></p><p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#215868">Anil Kumar – </span></b><b><span style="font-size:11.0pt;color:#215868">Sr. </span></b><b><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#215868">Software Developer</span></b><u></u><u></u></p>
<p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#00a1da">OceanManager</span></b><b><i><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#215868"> </span></i></b><b><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#00a1da">Inc.</span></b><b><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#009bd2"> </span></b><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:black">| </span><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><a href="http://www.oceanmanager.com/" target="_blank">www.oceanmanager.com</a></span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:11.0pt;color:#ed7d31">Tel: <a href="tel:%2B%2091-172-5026090" target="_blank">+ 91-172-5026090</a>, 5026091, 4646070</span><u></u><u></u></p><p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#00a1da">OceanManager- Marine Software</span></b><u></u><u></u></p>
</div><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span><u></u><u></u></p><div><div style="border:none;border-top:solid #e1e1e1 1.0pt;padding:3.0pt 0in 0in 0in">
<p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:"Calibri","sans-serif"">From:</span></b><span style="font-size:11.0pt;font-family:"Calibri","sans-serif""> <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>Anil Kumar<br>
<b>Sent:</b> Friday, June 27, 2014 12:55 PM<br><b>To:</b> <a href="mailto:jma@cola.iges.org" target="_blank">jma@cola.iges.org</a>; 'GrADS Users Forum'<br><b>Subject:</b> Re: [gradsusr] Help on calculating Area Maximum from NetCDF file using Grads</span><u></u><u></u></p>
</div></div><div><div><p class="MsoNormal"> <u></u><u></u></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Hi Jennifer and All,</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Am seeking help on calculating area maximum with linear interpolation using Grads. Earlier I was using below methodology to calculate area average over small areas defined. It was working good but now I need to calculate amax using lterp in grads <a href="http://www.iges.org/grads/gadoc/gradfunclterp.html" target="_blank">but in documentation I cannot find that ltrep uses amax as argument</a> ; neither it is giving correct result nor giving error.</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span><u></u><u></u></p><p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">My Requirement</span></b><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> : I have a larger dataset (.NC file) 1440*720 points. I want a new destination grid with linear interpolation having all the all area maximum values using amax() of small-small regions. And ultimately, need to query the destination grid for output.</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span><u></u><u></u></p><p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">What Am doing so far : </span></b><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">I have a NetCDF file having below CTL Info.</span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">*****************************************************************</span><u></u><u></u></p><p class="MsoNormal">
<span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">dset D:\WeatherGribFiles\2014\06\22\<a href="http://rtofs_glo_2ds_f024_daily_prog.nc" target="_blank">rtofs_glo_2ds_f024_daily_prog.nc</a></span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">title 2D Sfc Daily Prognostic 00Z22jun2014: Forecast, downloaded Jun 22 15:20 UTC</span><u></u><u></u></p><p class="MsoNormal">
<span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">undef 1.26765e+30</span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">dtype netcdf</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">xdef 1440 linear 74.16 0.24999</span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">ydef 720 linear -90 0.24999</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">zdef 1 linear 1 1</span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">tdef 1 linear 00Z23JUN2014 1mn</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">vars 2</span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">u_velocity=>u_velocity 1 t,z,y,x eastward_sea_water_velocity (m/s)</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">v_velocity=>v_velocity 1 t,z,y,x northward_sea_water_velocity (m/s)</span><u></u><u></u></p><p class="MsoNormal">
<span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">endvars</span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">*****************************************************************</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">I want a new destination grid ; which would contain the area maximum values as points. Destination grid should contain maximum value from every 8 points in x-axis and y axis. For this, I have created below, CTL file named as <b>rtofs_glo_2ds_f024_daily_prog.ctl</b>:</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">*****************************************************************</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">dset D:\WeatherGribFiles\2014\06\22\<a href="http://rtofs_glo_2ds_f024_daily_prog.nc" target="_blank">rtofs_glo_2ds_f024_daily_prog.nc</a></span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">index D:\WeatherGribFiles\2014\06\22\<span style="color:red">rtofs_glo_2ds_f024_daily_prog_DUMMY.nc </span></span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">title 2D Sfc Daily Prognostic 00Z22jun2014: Forecast, downloaded Jun 22 15:20 UTC </span><u></u><u></u></p><p class="MsoNormal">
<span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">undef 1.26765e+30 </span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">dtype netcdf </span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif";background:yellow">xdef 180 linear 74.16 2.0 </span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif";background:yellow">ydef 90 linear -90 2.0</span><span style="font-size:10.0pt;font-family:"Calibri","sans-serif""> </span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">zdef 1 linear 1 1 </span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">tdef 1 linear 00Z23JUN2014 1mn</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">options template </span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">vars 2 </span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">u_velocity=>u_velocity 1 t,z,y,x eastward_sea_water_velocity (m/s) </span><u></u><u></u></p><p class="MsoNormal">
<span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">v_velocity=>v_velocity 1 t,z,y,x northward_sea_water_velocity (m/s) </span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">endvars</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">*****************************************************************</span><u></u><u></u></p><p class="MsoNormal">
<span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Below is the command I use to display the data from destination grid <b>rtofs_glo_2ds_f024_daily_prog_DUMMY.nc </b>defined in above CTL file. Below is the command set using.</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">*****************************************************************</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">reinit</span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">sdfopen D:/WeatherGribFiles/2014/06/22/<a href="http://rtofs_glo_2ds_f024_daily_prog.nc" target="_blank">rtofs_glo_2ds_f024_daily_prog.nc</a></span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">open D:/WeatherGribFiles/2014/06/22/rtofs_glo_2ds_f024_daily_prog2.ctl</span><u></u><u></u></p><p class="MsoNormal">
<span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">set parea 0 11 0 8.5</span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">set vpage 0 11 0 8.5</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">set lon -74.16 434</span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">set lat -90 90</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">set cthick 6</span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">set arrscl 0.10 </span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">define val = mag(lterp(u_velocity.1*1.95,lat.2,amax),lterp(v_velocity.1*1.95,lat.2,amax))</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif"">d lterp(u_velocity.1*1.95,lat.2,amax);lterp(v_velocity.1*1.95,lat.2,amax);val</span><u></u><u></u></p><p class="MsoNormal">
<span style="font-size:10.0pt;font-family:"Calibri","sans-serif""> </span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">*****************************************************************</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">When I change the destination grid dimensions slightly in <b>rtofs_glo_2ds_f024_daily_prog.ctl </b>file</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif";background:yellow">xdef 135 linear 74.16 2.5 </span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif";background:yellow">ydef 68 linear -90 2.5</span><span style="font-size:10.0pt;font-family:"Calibri","sans-serif""> </span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">and checks for the output, It varies at the same point i.e. if I look at certain point before changing and after changing grid dimensions, the result comes of different magnitude.</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">What I want is, When I increase or decrease the destination grid points in “<b>rtofs_glo_2ds_f024_daily_prog.ctl”, </b>and the maximum value should be at its place. </span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">How can I achieve this ????? </span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span><u></u><u></u></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Thanks for any guidance.</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span><u></u><u></u></p><div><p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#215868">Thanks & Regards</span></b><u></u><u></u></p>
<p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#215868">Anil Kumar</span></b><u></u><u></u></p></div></div></div></div></div><p class="MsoNormal" style="margin-bottom:12.0pt">
<br>_______________________________________________<br>gradsusr mailing list<br><a href="mailto:gradsusr@gradsusr.org" target="_blank">gradsusr@gradsusr.org</a><br><a href="http://gradsusr.org/mailman/listinfo/gradsusr" target="_blank">http://gradsusr.org/mailman/listinfo/gradsusr</a><u></u><u></u></p>
</blockquote></div><p class="MsoNormal"><br><br clear="all"><u></u><u></u></p><div><p class="MsoNormal"><u></u> <u></u></p></div><p class="MsoNormal">-- <br><span style="font-size:24.0pt;font-family:"Arial","sans-serif";color:#006600">Arlindo da Silva</span><br>
<i><span style="font-size:13.5pt"><a href="mailto:dasilva@alum.mit.edu" target="_blank">dasilva@alum.mit.edu</a></span></i> <u></u><u></u></p></div></div></div></div></div></div></blockquote></div><br><br clear="all"><div>
<br></div>-- <br><font face="'comic sans ms', sans-serif" size="6" color="#006600"><span style="font-family:Helvetica;font-size:12px"></span><span></span><span></span>Arlindo da Silva</font><br><font size="4"><i><a href="mailto:dasilva@alum.mit.edu" target="_blank">dasilva@alum.mit.edu</a></i></font>
</div></div>