[Support #ZDT-182699]: PV in IDV

Hi Jim-

> That's interesting.  I haven't had a chance to download the latest
> build yet.  Is last nights OK except for the sign error?  Send me the
> URL again.

Last night's is okay except for the sign error.  You can grab it at:

http://www.unidata.ucar.edu/downloads/idv/nightly/

Don

 
> Unidata IDV Support wrote:
> > Hi Jim-
> >
> > I have a met question for you.  If I negate the grid for the GFS, I get 
> > what I would consider as correct results.  However, for the NAM, the values 
> > are then wrong.
> >
> > If you download the nightly build and run the Displays->Favorite 
> > Bundles->NAM211->Isentropic Potential Vorticity bundle, you should get a 
> > reasonable depiction.  Can you confirm this?
> >
> > However, if you do a GFS isosurface, the values are negated.  If you set 
> > the isosurface value to -2, it should look like the NAM 2 IPVunit surface.  
> >  The GEMPAK formula is:
> >
> > -GRAVTY*AVOR(V)*dTheta/dP
> >
> > There was a note in the code that using the - gives the wrong values, but 
> > I'm stumped as to way it works with one grid and not the other. Both are 
> > GRIB1, both have a vertical dimension of P in hectopascals.  Any thoughts 
> > on this?
> >
> > I'll keep looking into it, but thought I'd turn to a professional for some 
> > advice.
> >
> > In the meantime, you can just use the -2 isosurface for the GFS. ;-)
> >
> > Don
> >
> >
> >>> I was trying to plot an isosurface.  That "works", but the result is
> >>> best described as "gobbledygook."  The ability to do a 2 PVU isosurface
> >>> is really powerful for teaching PV thinking.  That's when I noticed the
> >>> error.
> >>>
> >> I found one error which was that absolute vorticity was being calculated 
> >> incorrectly.  That will be fixed in the nightly build.  However, I'm now 
> >> trying to get IPV correct. I compared the results from GEMPAK and they 
> >> match.
> >>
> >> However, IPV is even worse now. :-( I'll have to do some plan view plots 
> >> in GEMPAK to compare with since I don't have any other program to show 
> >> what the isosurface should look like.
> >>
> >> Thanks for your patience.
> >>
> >> Don
> >>
> >>
> >>> Unidata IDV Support wrote:
> >>>
> >>>> Hi Jim-
> >>>>
> >>>> I've moved this to the support system.  Best to send questions to 
> >>>> support-idv instead of me directly so we can better track these issues.
> >>>>
> >>>> Thanks for catching this. Did this ever work?  I've always done this as 
> >>>> a volume since IPV needs several levels. If you select 2 (or more) 
> >>>> levels in the levels panel, you'll be able to do the slice for a plan 
> >>>> view.  However, the list of levels in the control will not reflect the 
> >>>> levels you selected, but the entire list of levels.  We're working on a 
> >>>> fix to this.
> >>>>
> >>>> Don
> >>>>
> >>>>
> >>>>
> >>>>> ERROR: Creating display: Contour Plan View
> >>>>> org.python.core.PyException
> >>>>> Traceback (innermost last):
> >>>>> File "<string>", line 1, in ?
> >>>>> at visad.FlatField.derivative(FlatField.java:4044)
> >>>>> at visad.FlatField.derivative(FlatField.java:4485)
> >>>>> at
> >>>>> ucar.unidata.data.grid.DerivedGridFactory.partial(DerivedGridFactory.java:2366)
> >>>>> at
> >>>>> ucar.unidata.data.grid.DerivedGridFactory.createIPV(DerivedGridFactory.java:1954)
> >>>>> at
> >>>>> ucar.unidata.data.grid.DerivedGridFactory.createIPV(DerivedGridFactory.java:1880)
> >>>>> 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:597)
> >>>>>
> >>>>> visad.VisADException: visad.VisADException: derivative: d_partial_s not
> >>>>> in domain or reference
> >>>>> ERROR: Creating display: Contour Plan View
> >>>>> org.python.core.PyException
> >>>>> Traceback (innermost last):
> >>>>> File "<string>", line 1, in ?
> >>>>> at visad.FlatField.derivative(FlatField.java:4044)
> >>>>> at visad.FlatField.derivative(FlatField.java:4485)
> >>>>> at
> >>>>> ucar.unidata.data.grid.DerivedGridFactory.partial(DerivedGridFactory.java:2366)
> >>>>> at
> >>>>> ucar.unidata.data.grid.DerivedGridFactory.createIPV(DerivedGridFactory.java:1954)
> >>>>> at
> >>>>> ucar.unidata.data.grid.DerivedGridFactory.createIPV(DerivedGridFactory.java:1880)
> >>>>> 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:597)
> >>>>>
> >>>>> visad.VisADException: visad.VisADException: derivative: d_partial_s not
> >>>>> in domain or reference
> >>>>>
> >>>>>
> >>>>>
> >>>>>
> >>>> Ticket Details
> >>>> ===================
> >>>> Ticket ID: ZDT-182699
> >>>> Department: Support IDV
> >>>> Priority: Normal
> >>>> Status: Open
> >>>>
> >>>>
> >>>>
> >>>
> >
> >
> > Ticket Details
> > ===================
> > Ticket ID: ZDT-182699
> > Department: Support IDV
> > Priority: Normal
> > Status: Open
> >
> >
> 
> 


Ticket Details
===================
Ticket ID: ZDT-182699
Department: Support IDV
Priority: Normal
Status: Open