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Re: [ferret_users] seeing some strange output in curvilinear grids

The CF standard for NetCDF datasets does not allow missing data in coordinate variables. Ferret should issue an error message when there is missing data in the longitude or latitude coordinate variables for the 3-argument plot commands. So in general, we'd expect to have seen this:

yes? fill variable, longitude, latitude
 **ERROR: value out of legal range: X coordinates
          missing value where val is needed

Your dataset is being read in such a way that the missing-value flag is not used quite correctly at the point within Ferret where that is being tested. Ferret should be able to have handled it, so there is a bug, and I see what its fix will be.

As an aside, a couple of comments about your dataset: The hdf-5 dataset is accessed by hdf5 through the netcdf-4 library, and so we can read the data in Ferret. It's not quite conforming to the CF standard. For instance, when you open the dataset, you'll see

yes? use satellite_missing_xcoords_ycoords.h5
 *** NOTE: Internal err: unknown data type

The data type of the variable IMG_WV is not coming through the netCDF calls as of the recognized data types SHORT, INT, FLOAT, etc. Overall things seem to work fine, but there may be details to deal with; for instance if you wanted to write a subset of the data using Ferret, you'd need to set the output type

yes?  save/outtype=int/file=subset.nc  img_wv[i=1:400,j=1:400]


On 2/21/2014 5:52 AM, Ghansham Sangar wrote:

Hi All

Kindly see this one.
I am trying to plot a curvilinear dataset
This is an hdf5 product that follows Netcdf-4 classic data model
and CF conventions.
I am able to open it.
But there are a few issues.
Kindly check attached files.


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