# [IDV #GZD-145979]: Sum of base reflectivity

• Subject: [IDV #GZD-145979]: Sum of base reflectivity
• From: "Unidata IDV Support" <address@hidden>
• Date: Mon, 19 Nov 2012 13:00:15 -0700

```> Full Name: Adam Smith
> Organization: University of Rhode Island
> Package Version: 3.1 build date:2012-08-31 20:26 UTC
> Operating System: Windows 7
> Hardware: Java: home: C:\Program Files (x86)\Java\jre7 version: 1.7.0_05
> j3d:1.5.2 fcs (build4)
> Description of problem: Creating display: Radar Sweep View in 2D
> No data selected
>
> Hello,
>
> I'm not sure if what I'm trying to do will make any sense, but I'd like to
> write a Jython formula that sums the total base reflectivity of a given
> NEXRAD III radar image.  The purpose is to relate changes in total
> reflectivity over time to migratory bird and bat activity.  I have no
> experience with Python.  Thanks very much for any assistance you can offer.
>

The suggestion is to write the summation out, you can add  a Jython
formula like the following and write the summation.

c=', '
print " output file is: ", ofile
output = open(ofile,'w')
output.write('(index) -> (Time, Sum)'+'\n')
newData = data.clone();
for t in range(newData.getDomainSet().getLength()):
timeStep = newData.getSample(t)
rvalues = timeStep.getValues()
sum = 0
for x in rvalues[0]:
if(str(x) != ('nan')):
sum = sum + x;
print sum
output.write(str(t)+c+'0 '+'\n');
output.close()
return

This is not fully tested, you may need to tweak a little.

>
> ******************
> Stack trace:
> java.lang.IllegalStateException: No data selected
> at ucar.unidata.idv.ui.IdvUIManager.selectDataChoices(IdvUIManager.java:5599)
> at
> ucar.unidata.idv.IntegratedDataViewer.selectDataChoices(IntegratedDataViewer.java:1016)
> at
> ucar.unidata.data.DerivedDataChoice.collectOperands(DerivedDataChoice.java:558)
> at ucar.unidata.data.DerivedDataChoice.getData(DerivedDataChoice.java:733)
> at ucar.unidata.data.DataChoice.getData(DataChoice.java:637)
> at ucar.unidata.data.DataInstance.getData(DataInstance.java:243)
> at ucar.unidata.data.DataInstance.getData(DataInstance.java:207)
> at ucar.unidata.data.grid.GridDataInstance.init(GridDataInstance.java:205)
> at ucar.unidata.data.grid.GridDataInstance.<init>(GridDataInstance.java:162)
> at ucar.unidata.data.grid.GridDataInstance.<init>(GridDataInstance.java:143)
> at
> ucar.unidata.idv.control.GridDisplayControl.doMakeDataInstance(GridDisplayControl.java:284)
> at
> at
> ucar.unidata.idv.control.DisplayControlImpl.initializeDataInstance(DisplayControlImpl.java:3201)
> at
> ucar.unidata.idv.control.DisplayControlImpl.setData(DisplayControlImpl.java:3183)
> at ucar.unidata.idv.control.PlanViewControl.setData(PlanViewControl.java:643)
> at
> at ucar.unidata.idv.control.PlanViewControl.init(PlanViewControl.java:473)
> at
> ucar.unidata.idv.control.DisplayControlImpl.init(DisplayControlImpl.java:1450)
> at
> ucar.unidata.idv.control.DisplayControlImpl.init(DisplayControlImpl.java:1131)
> at ucar.unidata.idv.ControlDescriptor.initControl(ControlDescriptor.java:986)
> at ucar.unidata.idv.ControlDescriptor\$1.run(ControlDescriptor.java:911)
> at ucar.unidata.util.Misc\$3.run(Misc.java:1250)
>
>
>

Ticket Details
===================
Ticket ID: GZD-145979
Department: Support IDV
Priority: High
Status: Closed

```

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