Re: [idvusers] Jython method to extract isosurface?

Hi Don,

After some further thought, perhaps I am not taking the best approach.
Even if one is content with folds rendered as discontinuities on a 2d grid,
any mapping algorithm will still have to decide which part of the fold to
ignore.

Thanks again for your help,

Paul





On 11 December 2013 07:51, Don Murray (NOAA Affiliate)
<don.murray@xxxxxxxx>wrote:

> Paul-
>
> There is no easy way/method.  Even using Gridded3DSet is not simple
> because you would need to pass the grid domain through all the logic in the
> VisAD methods that compute an appropriate Gridded3DSet for the computation.
>
> Don
>
>
> On 12/10/13 1:40 PM, Paul Graham wrote:
>
>> Hi Tom/Don,
>>
>> I had in mind to obtain the heights of the wet-bulb freezing level
>> surface, which is why I was thinking it would be nice if there was an
>> isosurface method that would return the heights of the surface.  I think
>> all one can do with folded areas is be content with a discontinuity in
>> any 2d representation, though a discontinuity might not be the result of
>> a fold.
>>
>> Paul
>>
>>
>> On 11 December 2013 02:13, Don Murray (NOAA Affiliate)
>> <don.murray@xxxxxxxx <mailto:don.murray@xxxxxxxx>> wrote:
>>
>>     All-
>>
>>     Gridded3DSet would return you a geometry in VisAD coordinates and
>>     you could then convert those to lat/lon/alt by running them through
>>     the MapProjectionDisplay's coordinate system (fromReference), I
>>     would presume.  But tom's point is valid in that you can't always
>>     map an isosurface to a 2D surface.  Even a "simple" field like
>>     temperature might have folds where there are inversions.
>>
>>     Don
>>
>>
>>     On 12/10/13 8:08 AM, Tommy Jasmin wrote:
>>
>>         On 12/10/13 8:52 AM, Tom Whittaker wrote:
>>
>>             Paul -- I don't know of anything off-hand.  One issue I see
>>             is if
>>             there is a fold in the isosurface, a 2D representation is
>>             impossible.
>>             For example, think of an isosurface of wind speed for, say,
>>             the 40kt
>>             isosurface -- they would be "tubes" and "bubbles"...
>>
>>             tom
>>
>>             On Mon, Dec 9, 2013 at 11:47 PM, Paul Graham
>>             <meteorpaul@xxxxxxxxx <mailto:meteorpaul@xxxxxxxxx>>
>>
>>             wrote:
>>
>>                 Hi IDV'ers,
>>
>>                 I'm interested to know if there is a way to extract an
>>                 isosurface
>>                 from a 3d
>>                 gridded field and store it as a 2d grid of isosurface
>>                 heights for
>>                 display
>>                 or other purposes, using an IDV Jython script?
>>
>>                 Any help is appreciated.
>>
>>                 Thanks,
>>
>>                 Paul
>>                 _________________________________________________
>>
>>
>>
>>         Hi guys - you are probably both aware but just to be sure, the
>> VisAD
>>         Gridded3DSet
>>         class does have methods to extract both isosurfaces and isolines :
>>
>>         http://www.ssec.wisc.edu/__visad-docs/javadoc/visad/__
>> Gridded3DSet.html
>>
>>         <http://www.ssec.wisc.edu/visad-docs/javadoc/visad/
>> Gridded3DSet.html>
>>
>>
>>     --
>>     Don Murray
>>     NOAA/ESRL/PSD and CU-CIRES
>>     303-497-3596
>>     http://www.esrl.noaa.gov/psd/__people/don.murray/
>>     <http://www.esrl.noaa.gov/psd/people/don.murray/>
>>
>>
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>>
>>
>>
>> --
>> Paul Graham
>> Email: meteorpaul@xxxxxxxxx <mailto:meteorpaul@xxxxxxxxx>
>> Mobile: 0403003784
>>
>
> --
> Don Murray
> NOAA/ESRL/PSD and CU-CIRES
> 303-497-3596
> http://www.esrl.noaa.gov/psd/people/don.murray/
>



-- 
Paul Graham
Email: meteorpaul@xxxxxxxxx
Mobile: 0403003784