<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">That kind of data grid (with 2-dimensional coordinate variables) doesn't fit the current gridded data model in GrADS. We have talked about implementing a new data model, quasi-regular data, that would fall somewhere in between regular grids and station data. But that is not likely to be implemented any time soon. For now, interpolating to a regular grid with PDEF is the only way to handle that kind of data directly using GrADS. <div>--Jennifer<br><div><br><div><div>On Sep 10, 2009, at 11:37 AM, Christopher Lynnes wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div>Jennifer,<br> The PDEF GENERAL capability looks quite useful, but made me wonder<br>if GrADS does or will support variable grids in netCDF, where the data<br>are defined according to the CF-1 convention for two-dimensional<br>latitude and longitude coordinate variables (<a href="http://cf-pcmdi.llnl.gov/documents/cf-conventions/1.4/cf-conventions.html#id2984605">http://cf-pcmdi.llnl.gov/documents/cf-conventions/1.4/cf-conventions.html#id2984605</a><br>).<br> We have a service to convert our AIRS swath data to netCDF files<br>with this convention, which allows tools such as IDV and McIDAS-V to<br>read and project them. However, attempting an sdfopen in grads<br>2.0.a7.1 leads to the "no discernable X coordinate" error.<br> An example file can be obtained via the URL:<br><a href="http://aurapar2u.ecs.nasa.gov/airspar1/daac-bin/OTF/HTTP_services.cgi?FILENAME=%2Fdata%2Fs4pa%2FAqua_AIRS_Level2%2FAIRX2RET.005%2F2006%2F161%2FAIRS.2006.06.10.202.L2.RetStd.v5.0.14.0.G07345043455.hdf&LABEL=AIRS.2006.06.10.202.L2.RetStd.v5.0.14.0.G07345043455.nc&SHORTNAME=AIRX2RET&SERVICE=NetCDF&VERSION=1.02">http://aurapar2u.ecs.nasa.gov/airspar1/daac-bin/OTF/HTTP_services.cgi?FILENAME=%2Fdata%2Fs4pa%2FAqua_AIRS_Level2%2FAIRX2RET.005%2F2006%2F161%2FAIRS.2006.06.10.202.L2.RetStd.v5.0.14.0.G07345043455.hdf&LABEL=AIRS.2006.06.10.202.L2.RetStd.v5.0.14.0.G07345043455.nc&SHORTNAME=AIRX2RET&SERVICE=NetCDF&VERSION=1.02</a><br><br>On Sep 10, 2009, at 7:58 AM, Jennifer Adams wrote:<br><br><blockquote type="cite">You can use the PDEF GENERAL (aka PDEF FILE) option to tell GrADS<br></blockquote><blockquote type="cite">how to map each grid point in your 1-D vector into a 2-D lat/lon<br></blockquote><blockquote type="cite">grid. Please see http://www.iges.org/grads/gadoc/pdef.html<br></blockquote><blockquote type="cite">The example at the bottom of the page does something very similar to<br></blockquote><blockquote type="cite">what you'd like to do.<br></blockquote><blockquote type="cite">--Jennifer<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">On Sep 9, 2009, at 7:03 AM, Reto Stauffer wrote:<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite"><blockquote type="cite">Hy there<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">I try to plot some Satellite-Data with Grads. It was "no problem"<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">to produce a<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">netCDF file wich i can import into GrADS and display the test-<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">dataset.<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">But now i have a question up to you. Normaly GrADS plots only onto<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">a linear<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">Grid. My netCDF-File only contains a one-line-vector with longitude<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">and<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">latitude boundries.<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">Is there any possibility to import long/lat as a 2-D matrix wich<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">discribes my<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">own grid? I cannot found any good information about that.<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">Test-Dataset, int [0;10] with own colormap:<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">http://dudecom.ch/satpress/wp-content/uploads/2009/09/20090909_grads_colormapexample-543x400.png<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">If anyone has an idea it wold be great to send me a request.<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">Best regards<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">Reto, Austria<br></blockquote></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">--<br></blockquote><blockquote type="cite">Jennifer M. Adams<br></blockquote><blockquote type="cite">IGES/COLA<br></blockquote><blockquote type="cite">4041 Powder Mill Road, Suite 302<br></blockquote><blockquote type="cite">Calverton, MD 20705<br></blockquote><blockquote type="cite">jma@cola.iges.org<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite"><br></blockquote><br>--<br>Christopher Lynnes NASA/GSFC, Code 610.2<br>301-614-5185<br></div></blockquote></div><br><div apple-content-edited="true"> <span class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; text-align: auto; -khtml-text-decorations-in-effect: none; text-indent: 0px; -apple-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><div style="word-wrap: break-word; -khtml-nbsp-mode: space; -khtml-line-break: after-white-space; "><span class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; text-align: auto; -khtml-text-decorations-in-effect: none; text-indent: 0px; -apple-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><span class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; text-align: auto; -khtml-text-decorations-in-effect: none; text-indent: 0px; -apple-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><div>--</div><div>Jennifer M. Adams</div><div>IGES/COLA</div><div>4041 Powder Mill Road, Suite 302</div><div>Calverton, MD 20705</div><div><a href="mailto:jma@cola.iges.org">jma@cola.iges.org</a></div><div><br class="khtml-block-placeholder"></div><br class="Apple-interchange-newline"></span></span></div></span> </div><br></div></div></body></html>