[IDV #JYA-484656]: exponentiation - still struggling with Jython

Hi HP-

> Full Name: HansPeter Roesli
> Email Address: address@hidden
> Organization: EUMETSAT
> Package Version: 2.4b3 build date:@DATE@
> Operating System: Linux
> Hardware: Java: home: /home/user/IDV_2.4b3/jre version: 1.5.0_11 j3d:1.3.1
> Description of problem: Hi
> 
> I am still struggling with Jython. Consider the formula in the plugin. It 
> calls channels 9 (IR10.8)
> and channel 12 (HRV) of MSG data and does an RGB  mixing the 2 channels. Both 
> channel
> get gamma-corrected,i.e. their values are exponentiated with the factor at 
> the end of the ir
> scaling. This works fine for channel 9 (just delete the last part of the 
> channel-12
> lineto test it, i.e. **(1./1.7). However, I get an error for channel 12 when 
> adding this last part.

What calibration unit (Data Type) are you using?  I ran it with Ch 9 Temperature
and channel 12 brightness and it seemed to work.
 
> I do not understand the error message. Has it to do with differently sized 
> grids?

No, it's more like it can't handle the units that are created during the
exponentiation.  The only thing I can think of is that it is re-using an
existing VisAD  MathType which defines the units differently than  what
you are getting from the exponent.  This is a "problem" with VisAD in that
if you create a new field that has the same name as another one with different
units, you can end up with conflicts like this.  I'm not sure where this is
happening though since it seems to work for me.  Can you send me a bundle that
exhibits the behavior?  Does this always happen or does it work the first
time and not afterwards?

Thanks.

Don

> An error has occurred:
> Creating display: 3 Color (RGB) Image
> org.python.core.PyException
> 
> ******************
> Stack trace:
> Traceback (innermost last):
> File "<string>", line 1, in ?
> File "<string>", line 194, in TempHRV_RGB
> at visad.FlatField.<init>(FlatField.java:412)
> at visad.FlatField.cloneFloat(FlatField.java:5606)
> at visad.FlatField.binary(FlatField.java:3140)
> at visad.FieldImpl.binary(FieldImpl.java:849)
> at visad.DataImpl.binary(DataImpl.java:139)
> at visad.DataImpl.pow(DataImpl.java:231)
> at visad.DataImpl.__pow__(DataImpl.java:1505)
> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
> at 
> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
> at 
> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
> at java.lang.reflect.Method.invoke(Method.java:585)
> 
> visad.UnitException: visad.UnitException: FlatField: RangeUnits must be 
> convertable with RangeType default Units
> 
> 
> 


Ticket Details
===================
Ticket ID: JYA-484656
Department: Support IDV
Priority: Normal
Status: Open