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[THREDDS #TJM-446577]: Manipulation of data in IDV

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  • Subject: [THREDDS #TJM-446577]: Manipulation of data in IDV
  • Date: Thu, 28 Sep 2006 13:32:11 -0600
Hi Joseph-

I apologize for the delay in responding.

> >>> I have a couple of questions regarding the manipulation of data in IDV:
> >>>
> >>> 1. I want to derive grid data for locations similar to those of my
> >>> observation data. I know how to do this if the obseravtional data is in
> >>> netCDF, but is it also possible when it is in GIS (shapefile) format? In
> >>> other words, is there a way to get the grid information for the areas
> >>> overlapping with my shapefile programetically from within Jython for
> >>> example?

There are no techniques in the IDV for this type of spatial analysis
of finding which points in a grid are covered by a random polygon.
That is the strength of GIS packages.  

> >>> 2. If so, is there a way to specify the number of pixels/grids or
> >>> neighboring pixels which should be retrieved for the same location?

No.  The default sampling technique is described here:

http://www.unidata.ucar.edu/software/IDV/docs/userguide/Faq.html#faq1_cat4_24

You would have to override the gridToValue methods of the GriddedSets
to do a different sampling than NEAREST_NEIGHBOR or WEIGHTED_AVERAGE.

> >>> 3. If there are missing values in a grid data, is it possible to assign
> >>> the values of neighboring pixels, or defining a spatial offset to
> >>> include grid cells that surround those with missing values closest to my
> >>> location?

I'm not aware of a way to do this unless you looked at every point
and assigned the value based on some scheme of your choosing.

Don Murray


Ticket Details
===================
Ticket ID: TJM-446577
Department: Support IDV
Priority: Emergency
Status: Open