Re: [idvdevelopers] [idvusers] problem using Contour2DDisplayable

• To: Stuart Maclean <stuart@xxxxxxxxxxxxxxxxxx>
• Subject: Re: [idvdevelopers] [idvusers] problem using Contour2DDisplayable
• From: Don Murray <dmurray@xxxxxxxxxxxxxxxx>
• Date: Fri, 04 Apr 2008 08:22:22 -0600

Hi Stuart-

Just a followup to this since I'm now looking at your first
message.  In your code you have:


Stuart Maclean wrote:

I am now trying to contour a field from a netcdf grid file. The IDV does this Ok, but my image is simply a white polygon of the grid itself. My code is this:

        String netcdfUrl = args[0];
        GeoGridDataSource ggds = new GeoGridDataSource(null, netcdfUrl, null);
        GridDataset gds = ggds.getDataset();
        GeoGrid gg = (GeoGrid)gds.getGrids().get(0);

This will just get the first grid in the GridDataset.  What you want
to do is:

        GeoGrid gg = gds.findGridByName("surface_temperature");

(or substitute whatever the variable name is for "surface_temperature").

        GeoGridAdapter gga = new GeoGridAdapter( ggds, gg,
                                                 "surface_temperature" );
        FieldImpl fi = gga.getData();
        System.out.println( fi.getType().prettyString() );

which gives

(Time -> ((XC[unit:km], YC[unit:km]) -> surface_temperature[unit:Pa]))

Not sure why temp units are Pa??

The first grid in the GridDataset must be a pressure grid of
some sort.

        FlatField ff = (FlatField)fi.getSample(1);
        System.out.println( ff.getType().prettyString() );

which I presume extracts some time element, and gives

((XC[unit:km], YC[unit:km]) -> surface_temperature[unit:Pa])

Don
*************************************************************
Don Murray                               UCAR Unidata Program
dmurray@xxxxxxxxxxxxxxxx                        P.O. Box 3000
(303) 497-8628                              Boulder, CO 80307
http://www.unidata.ucar.edu/staff/donm
*************************************************************

• Follow-Ups:
  • Re: [idvdevelopers] [idvusers] problem using Contour2DDisplayable
    • From: Stuart Maclean