Re: [idvusers] Grid interpolation in IDV

Hi Tom,

Thanks for the method you posted for finding a field value at a lat/lon.  I
tried it and it worked a treat!  A function that returns a field value at a
specific point would be very useful in diagnoses.  Perhaps one could be
included as part of one of the IDV Jython System libraries?

Paul

On 4 January 2013 02:26, Tom Whittaker <whittaker@xxxxxxxx> wrote:

> Paul --
>
> The simplest way to extract a value at a given lat/lon location might
> be something like this (I'm assuming you're in the Jython Shell at
> this point...):
>
> 1. a = selectData()
>            [then pick your gridded field -- if it's 3D then you'll
> need to use the "make2D()"
>            function in the Jython library "Grid routines"]
>
> 2. assuming there is a "time" dimension, then do:
>        b = a[0]
>
>     (if you do a "print len(a)" and the answer is a small number, like
> "1", then you likely have a time dimension...you can also do "print
> whatTypes(a)" and get the details of the structure of 'a')
>
> 3. then (welcome to the World of VisAD):
>
>       from visad.georef import LatLonTuple
>
> 4. now for each point do this:
>        print b.evaluate( LatLonTuple( 43., -89.))
>
> (using your own lat/lon values....)
>
> tom
>
> On Wed, Jan 2, 2013 at 11:45 PM, Paul Graham <meteorpaul@xxxxxxxxx> wrote:
> > Hi Stuart,
> >
> > In hindsight, contours were not a good example of what I am wanting.
>  What I
> > am wanting is to be able to interpolate gridded data sets, so I can put
> in a
> > lat/lon and obtain a field value, preferably using a Jython method.  It
> > would be good if IDV has a Jython method that could do this.
> >
> > Paul Graham
> >
>
> --
> Tom Whittaker
> University of Wisconsin-Madison
> Space Science & Engineering Center (SSEC)
> Cooperative Institute for Meteorological Satellite Studies (CIMSS)
> 1225 W. Dayton Street
> Madison, WI  53706  USA
> ph: +1 608 262 2759
>