<div>Hi Mitias</div>
<div> </div>
<div>You can use cdo to separate your variables into separate files and use the GrADS for analysis.</div>
<div> </div>
<div>Here is cdo command to do it:</div>
<div> </div>
<div>cdo selname,variableName ifilename ofilename</div>
<div> </div>
<div>e.g. cdo selname,precip <a href="http://combined.nc">combined.nc</a> <a href="http://precip.nc">precip.nc</a> </div>
<div>(take it just as an example,,,because the variable names might be diffrent in your file)</div>
<div> </div>
<div>Hope it works,,,</div>
<div> </div>
<div>Cheers</div>
<div>Rashed Mahmood</div>
<div><font size="1">Institute of Atmospheric Physics</font></div>
<div><font size="1">Chinese Academy of Sciences</font></div>
<div><font size="1">Beijing, China.</font></div>
<div> </div>
<div><br> </div>
<div class="gmail_quote">On Fri, Nov 19, 2010 at 10:40 PM, Matias Mendez <span dir="ltr"><<a href="mailto:matias.mendezp@gmail.com">matias.mendezp@gmail.com</a>></span> wrote:<br>
<blockquote style="BORDER-LEFT: #ccc 1px solid; MARGIN: 0px 0px 0px 0.8ex; PADDING-LEFT: 1ex" class="gmail_quote">Dear Jennifer,<br><br>Thank you for your response. Sorry I forgot to provide more<br>information. I'm using GrADS version 2.0.a7 oga.3 on linux (fedora<br>
10) and this configuration:<br><br>ga-> q config<br>Config: v2.0.a7.oga.3 little-endian readline printim grib2 netcdf<br>hdf4-sds hdf5 opendap-grids,stn athena geotiff<br>Grid Analysis and Display System (GrADS) Version 2.0.a7.oga.3<br>
Copyright (c) 1988-2009 by Brian Doty and the<br>Institute for Global Environment and Society (IGES)<br>This program is distributed WITHOUT ANY WARRANTY<br>See file COPYRIGHT for more information.<br><br>Built Thu Oct 29 17:28:29 EDT 2009 for i686-pc-linux-gnu<br>
<br>This version of GrADS has been configured with the following options:<br> o Built on a LITTLE ENDIAN machine<br> o Command line editing ENABLED<br> <a href="http://tiswww.case.edu/php/chet/readline/rltop.html" target="_blank">http://tiswww.case.edu/php/chet/readline/rltop.html</a><br>
o printim command for image output ENABLED<br> <a href="http://www.zlib.net/" target="_blank">http://www.zlib.net</a><br> <a href="http://www.libpng.org/pub/png/libpng.html" target="_blank">http://www.libpng.org/pub/png/libpng.html</a><br>
<a href="http://www.libgd.org/Main_Page" target="_blank">http://www.libgd.org/Main_Page</a><br> o GRIB2 interface ENABLED<br> <a href="http://www.ijg.org/" target="_blank">http://www.ijg.org</a><br> <a href="http://www.ece.uvic.ca/~mdadams/jasper" target="_blank">http://www.ece.uvic.ca/~mdadams/jasper</a><br>
<a href="http://www.nco.ncep.noaa.gov/pmb/codes/GRIB2" target="_blank">http://www.nco.ncep.noaa.gov/pmb/codes/GRIB2</a><br> g2clib-1.0.5<br> o NetCDF interface ENABLED<br> <a href="http://www.opendap.org/" target="_blank">http://www.opendap.org</a><br>
libnc-dap 4.0.1-beta3-snapshot2009021712 of Feb 21 2009 14:55:15 $<br> o HDF interface ENABLED<br> <a href="http://hdfgroup.org/" target="_blank">http://hdfgroup.org</a><br> HDF 4.2r3<br> HDF5 1.8.2<br> o Athena Widget GUI ENABLED<br>
o OPeNDAP gridded data interface ENABLED<br> <a href="http://www.opendap.org/" target="_blank">http://www.opendap.org</a><br> libdap 3.7.10<br> o OPeNDAP station data interface ENABLED<br> <a href="http://iges.org/grads/gadoc/supplibs.html" target="_blank">http://iges.org/grads/gadoc/supplibs.html</a><br>
libgadap 2.0.oga.1<br> o GeoTIFF and KML output ENABLED<br> <a href="http://www.libtiff.org/" target="_blank">http://www.libtiff.org</a><br> <a href="http://geotiff.osgeo.org/" target="_blank">http://geotiff.osgeo.org</a><br>
<br><br>I'll try your suggestion (breaking up output). Is there any other<br>option (fortran, C, etc) to read and write a variable?<br><br>Thanks in advance.<br><br>Regards.<br><font color="#888888">Matias<br></font>
<div>
<div></div>
<div class="h5"><br><br>On Thu, Nov 18, 2010 at 8:18 AM, Jennifer Adams <<a href="mailto:jma@cola.iges.org">jma@cola.iges.org</a>> wrote:<br>> Whenever you submit a question, it is impossible to answer without knowing<br>
> two things: the version of GrADS you are running, and the platform you are<br>> running it on. THIS REALLY MATTERS!<br>> Your 'subset' file should be 10242422568 bytes (399*279*31*742*4)<br>> If it is not, then you can blame mm5_to_grads.sh -- maybe it doesn't have<br>
> the capability to write out a 9.5Gb file... Try breaking up your output into<br>> 742 separate files and template them together with GrADS.<br>> The error messages you're getting indicate that GrADS is having trouble<br>
> moving to the correct position in the file to fulfill your I/O request.<br>> Older versions of GrADS did not have the capability to read files > 2GB, but<br>> who can tell whether this is your problem because you didn't provide enough<br>
> information about your GrADS build.<br>> --Jennifer<br>><br>> On Nov 18, 2010, at 8:42 AM, Matias Mendez wrote:<br>><br>> Dear GrADS users,<br>><br>> I have a big MM5 output (~100GB, with 31 sigma-levels, 742 hourly time<br>
> steps, 23 variables). I have used mm5_to_grads.sh to extract a<br>> variable (u-wind). After that I tried to display this variable,<br>> everything was working fine but when I did:<br>><br>> d u(t=623)<br>
><br>> I got the following error mesage:<br>><br>> Notice: Automatic Grid Interpolation Taking Place<br>> Low Level I/O Error: Seek error on data file<br>> Data file name = /home/XXXXX/U_ENE-2006.dat<br>
> 523 rc=-1 fpos=-2145136144 pfi->fhdr=-1<br>> Error occurred when seeking to byte 9390016<br>> Data Request Error: Error for variable 'u'<br>> Error ocurred at column 1<br>> DISPLAY error: Invalid expression<br>
> Expression = u(t=623)<br>><br>> What does this mean this message and how can I solve this problem?.<br>> Is there another way to extract a variable from a big file?. Any<br>> sugesstion is welcome. Thanks in advance.<br>
><br>> Best regards,<br>> Matías<br>><br>> P.S.<br>> This is the ctl file created by mm5_to_grads.sh<br>><br>> dset /home/XXXXX/U_ENE-2006.dat<br>> byteswapped<br>> title MM5 data<br>> undef -9999.<br>
> pdef 399 279 lcc 24.00 -102.00 200.00 140.00 30.00 60.00 -102.00<br>> 900<br>> 0. 9000.<br>> xdef 972 linear -121.69 0.0405<br>> ydef 571 linear 12.15 0.0405<br>> zdef 31 levels<br>
> 0.99950<br>> 0.99800<br>> 0.99600<br>> 0.99400<br>> 0.99200<br>> 0.98950<br>> 0.98700<br>> 0.98500<br>> 0.98300<br>> 0.98100<br>> 0.97500<br>> 0.96000<br>> 0.94000<br>> 0.92000<br>
> 0.90500<br>> 0.89000<br>> 0.87000<br>> 0.85000<br>> 0.83000<br>> 0.81000<br>> 0.79000<br>> 0.76000<br>> 0.72000<br>> 0.68000<br>> 0.64000<br>> 0.61000<br>> 0.55000<br>> 0.45000<br>
> 0.35000<br>> 0.20000<br>> 0.05000<br>> tdef 742 linear 00:00Z01JAN2006 60MN<br>> vars 1<br>> u 31 99 u wind (m/s)<br>> endvars<br>><br>> _______________________________________________<br>
> gradsusr mailing list<br>> <a href="mailto:gradsusr@gradsusr.org">gradsusr@gradsusr.org</a><br>> <a href="http://gradsusr.org/mailman/listinfo/gradsusr" target="_blank">http://gradsusr.org/mailman/listinfo/gradsusr</a><br>
><br>> --<br>> Jennifer M. Adams<br>> IGES/COLA<br>> 4041 Powder Mill Road, Suite 302<br>> Calverton, MD 20705<br>> <a href="mailto:jma@cola.iges.org">jma@cola.iges.org</a><br>><br>><br>><br>
> _______________________________________________<br>> gradsusr mailing list<br>> <a href="mailto:gradsusr@gradsusr.org">gradsusr@gradsusr.org</a><br>> <a href="http://gradsusr.org/mailman/listinfo/gradsusr" target="_blank">http://gradsusr.org/mailman/listinfo/gradsusr</a><br>
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</div></div></blockquote></div><br>