# [IDV #APF-259524]: Calculating areas of contoured data

• Subject: [IDV #APF-259524]: Calculating areas of contoured data
• Date: Mon, 28 Sep 2015 17:05:39 -0600

```> Thank you for your reply. Hmmm sounds complicated but maybe plausible. I'll
> submit the question to idvusers... All the best, Alexa
>

Alexa,

Actually, there is way to do the area calculation manually. It may not
be very accurate since you need to manually
draw the line on the top of the contour line using the drawing control tool.
After drawing, go to the Drawing Control panel, and select
the Shapes tab, double click the Glyph, another window popup and you can see
the area there.

We should be able to add this as a Jython function, let me thinking about it
after this week (I am attending a conference this week ).

Yuan
>
> > Alexa,
> >
> > Good to hear from you again!
> >
> > To my knowledge, this will not be so easy in the IDV. Theoretically, you
> > could
> > apply a maskGrid formula in the IDV above a certain threshold.  Then you
> > would
> > have to calculate the area inside the closed curve. I see someone doing
> > this in
> > Python here:
> >
> >
> > http://stackoverflow.com/questions/22678990/how-can-i-calculate-the-area-within-a-contour-in-python-using-the-matplotlib
> >
> > so -- grasping at straws -- you may be able to do this in a Jython formula.
> >
> > Or you may be able to this in Python from the get-go. We could possibly
> > out here too (address@hidden). Also gis.stackexchange.com
> > could
> > be another good resource in this area.
> >
> > I would encourage you to open up this discussion by submitting your
> > question to
> >
> > Best,
> >
> > Unidata IDV Support
> >
> >
> > > Full Name: Alexa Van Eaton
> > > Organization: Arizona State University
> > > Package Version:
> > > Operating System:
> > > Hardware:
> > > Description of problem:
> > >
> > > I am trying to figure out of there is a way to calculate the area of a
> > > contour in IDV. For example, what is the area of the 255K temperature
> > > contour in the center of the attached satellite image? I also explored
> > > exporting that contour as a KML file to do the measurement in Google
> > > Earth, but it is exported as an image rather than a polyon (so I would
> > > need to re-trace it in Google Earth). Ideas for a workaround would
> > > be appreciated!
> > >
> > > Thank you
> > >
> >
> >
> > Ticket Details
> > ===================
> > Ticket ID: APF-259524
> > Department: Support IDV
> > Priority: Normal
> > Status: Closed
> >
> >
>
>
> --
> Alexa Van Eaton, Ph.D.
> Mendenhall Research Fellow
> U.S. Geological Survey
> David A. Johnston Cascades Volcano Observatory
> Vancouver, Washington
> Office (360) 993 8921
> https://profile.usgs.gov/avaneaton
>
>

Ticket Details
===================
Ticket ID: APF-259524
Department: Support IDV
Priority: Normal
Status: Open

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