OK. I see now. Clearly I'm not familiar with the GrADS software or its data formats. If someone else on the ParaView mailing list is familiar with GrADS it would be great if they speak up, but according to the mail archives GrADS has not yet been discussed.
I suspect the problem is that ParaView simply does not know how to read the type of netCDF files written by GrADS. NetCDF is not a completely specified file format. Rather, it is a collection of arrays that are "self describing." That is, the arrays and dimensions are named and can have properties, but to read them properly you really have to understand what these metadata mean. There are actually several readers in ParaView that use netCDF as the underlying technology, but only one that makes an attempt to generally read unknown "conventions." It will assume that arrays are regular grids with up to three physical dimensions (x/y/z or lat/lon/z) and optionally a time dimension. Based on about 5 minutes looking at the GrADS web pages, I'm guessing that the netCDF file GrADS is outputting contains 5 dimensional arrays. In this case, the ParaView reader won't know what to do with 5 dimensions and will therefore issue an error if you try to read one. (You never actually said what went wrong, but perhaps that is it.) I'm sorry that probably none of this is helping. Ultimately, it sounds like a new reader would have to be created for ParaView. -Ken On 3/13/12 2:28 AM, "wang" <[email protected]> wrote: >Thanks for your reply. > >Grads is a software package that widely used by meteorological societies > worldwide. http://www.iges.org/grads/. >The nc file I get can be shown by ferret (which is also a software >package >used by earth science communities) and Grads (Grads can read binary and >data). > >The problem may occurred by conversion... > >Xueli > >Moreland, Kenneth wrote: >> I don't know what you mean by a "grad" or what problem it is causing, so >> I'm going to make a total guess. I am guessing that you mean gradian (a >> unit equal to 9/10 of a degree). Furthermore, because I can't think of >> any other way such units would mess you up, I am guessing that you are >> trying to write spherical coordinates in terms of gradians, but ParaView >> is interpreting them either as degrees or as Cartesian coordinates. >> >> >> Assuming that this is the problem, it is caused by the fact that the >> default netCDF reader for ParaView honors the CF convention >> (http://cf-pcmdi.llnl.gov), and the CF convention specifies spherical >> coordinates in terms of degrees. To specify angles in any other units >>is >> to break the convention. >> >> Your best solution is to convert your gradians to degrees (it's OK to >>have >> floating-point degrees) and write a netCDF file that properly follows >>the >> CF convention. >> >> If I have completely missed the point of your question, you'll have to >> better explain what are grads and what problem you are having with them. >> >> -Ken >> >> On 3/12/12 10:13 AM, "wang"<[email protected]> wrote: >> >> >>> Dear Paraview users, >>> >>> I have problem with data that origin of grads. We have a program to >>> convert grads data into NetCDF format. But this data can not be shown >>>in >>> Paraview. I don't have any problem to show normal nc data. >>> >>> Have you ever experience the same problem? >>> >>> Thanks! >>> Xueli >>> _______________________________________________ >>> Powered by www.kitware.com >>> >>> Visit other Kitware open-source projects at >>> http://www.kitware.com/opensource/opensource.html >>> >>> Please keep messages on-topic and check the ParaView Wiki at: >>> http://paraview.org/Wiki/ParaView >>> >>> Follow this link to subscribe/unsubscribe: >>> http://www.paraview.org/mailman/listinfo/paraview >>> >>> >> >> > > _______________________________________________ Powered by www.kitware.com Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Please keep messages on-topic and check the ParaView Wiki at: http://paraview.org/Wiki/ParaView Follow this link to subscribe/unsubscribe: http://www.paraview.org/mailman/listinfo/paraview
