NOTICE: This version of the NSF Unidata web site (archive.unidata.ucar.edu) is no longer being updated.
Current content can be found at unidata.ucar.edu.
To learn about what's going on, see About the Archive Site.
NOTICE: This version of the NSF Unidata web site (archive.unidata.ucar.edu) is no longer being updated.
Current content can be found at unidata.ucar.edu.
To learn about what's going on, see About the Archive Site.
Tim et al.,Unless your data are from a particular simulation code or are defined on a rectilinear mesh, VisIt won't be able to understand them:
http://www.visitusers.org/index.php?title=Reading_NETCDFYou could also write a custom (NetCDF-based) reader for VisIt to understand whatever conventions you implement. As Rich says, the VisIt community would be happy to push you in the right direction via the visit-users mailing list:
https://elist.ornl.gov/mailman/listinfo/visit-users HTH, -tom On 03/27/2012 07:19 PM, Rich Signell wrote:
Tim, If you want to use VisIt with NetCDF files, you have to know what conventions VisIT expects so you can create VisIT-compatible NetCDF files. I seem to remember that they implement some of the CF conventions, but not all. The VisIt developers or community should be able to help you with this. -Rich On Tue, Mar 27, 2012 at 10:50 AM, Tim Duly<duly2@xxxxxxxxxxxx> wrote:Rich, Thank you for the information. My data comes from an unformatted Fortran file, and Python was the easiest way to read this data. I'd prefer to use VisIt as I'd like to extend this project with a 2D plot with time, and then to a 3D plot with time. Perhaps I wasn't clear enough-- I have all the data read into Python right now, but am having trouble writing the coordinate information into the NetCDF. I am able to get the actual data into VisIt, but it's not "applied" to the (200 x 100) matrix X and Y coordinate information. From my research, it doesn't look like NetCDF is able to do this. Perhaps I should be using another data format for VisIt? Thanks, Tim On Tue, Mar 27, 2012 at 9:20 AM, Rich Signell<rsignell@xxxxxxxx> wrote:Tim, You mention quite a few things here: unstructured grids, Matlab, NetCDF, CF, Python and Visit. If your goal is to truly to visualize unstructured grid data from NetCDF files (or OPeNDAP datasets) using Python, take a look at this screen shot using Mayavi2 http://dl.dropbox.com/u/12710282/Screenshot-Mayavi.png and the simple code that produced it: http://dl.dropbox.com/u/12710282/triangular_mesh_demo.py Mayavi2 comes with at least two scientific Python distributions: Python(x,y) (free, works on 32 bit windows) and the Enthought Python Distribution (free for educational use, works on 32/64 bit windows, mac and linux). You should be able to run the above python script without changes on either distribution. However, it sounds like you actually have structured grid data in a text file that you want to use. In python, I would use numpy "genfromtxt" to read from the text file, and visualize with Mayavi2's "surf" function. See: http://github.enthought.com/mayavi/mayavi/auto/examples.html If you want to save your data in a NetCDF file, I'd use the NetCDF4Python package (also included in the above scientific python distributions). This would allow you to visualize it in other tools as well, like Unidata's IDV. Good Luck, -Rich On Mon, Mar 26, 2012 at 3:31 PM, Tim Duly<duly2@xxxxxxxxxxxx> wrote:Hello, I have a relatively simple task. I have 2D data, of dimension 200x100 that belong to an unstructured grid that contains X and Y, both of which are dimension 200x100. In other words, I have DATA = f(X,Y). I'm trying to plot this in VisIt, but am having a tough time applying the unstructured grid to the actually data. In MATLAB, for example, this is easily accomplished with surf(X,Y,DATA), but I'm having difficulties finding the equivalent in NetCDF. How do I do this? Is this problem solved in NetCDF or in VisIt? I am using the Python library NetCDF to transform unformatted Fortran data into NetCDF format. I have read this page ( http://cf-pcmdi.llnl.gov/documents/cf-conventions/1.4/cf-conventions.html#id2984605 ) but I do not understand how to do this with the NetCDF library in python. Should I use another data format besides NetCDF? Any help would be greatly appreciated. Thanks, Tim _______________________________________________ netcdfgroup mailing list netcdfgroup@xxxxxxxxxxxxxxxx For list information or to unsubscribe, visit: http://www.unidata.ucar.edu/mailing_lists/-- Dr. Richard P. Signell (508) 457-2229 USGS, 384 Woods Hole Rd. Woods Hole, MA 02543-1598
netcdfgroup archives: