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[IDV #LCA-261543]: GrADS .ctl files

Hi Stefan-

> Certainly. Attached is the .ctl created for the 4km-nest domain of my
> most recent output. There were 3 nests(12km-4km-1.33km). If you need
> the .dat file, we will have to figure out some way  to transfer ~12gb
> of data. Have you seen/used ARWpost before? Thanks!

One problem is that the units are not being picked up correctly hence the 
incompatibility noted in the
error message. For the GrADS reader, I used the convention that the unit is 
between brackets, not parentheses, which seems to be more common.  It's hard to 
parse using the parens, because some variable names have comments in parens 
that are not units like this one in your file:

T             22  0  perturbation potential temperature (theta-t0) (K)

If you can process the CTL file so the units are in between brackets:

T             22  0  perturbation potential temperature (theta-t0) [K]

that should clear up that problem.

Another problem which might account for the screwy values is the "byteswapped" 
option.  For any given file, I don't know the "source" byte order vs. the order 
you are reading the data on so I don't know what order I should be reading in.  
There is a note near the bottom of the ARWpost page that says that this can 
cause problems:

http://www.mmm.ucar.edu/wrf/users/graphics/ARWpost/ARWpost.htm

try removing (or commenting out with a * at the beginning of the line).

Another option is to use WRFpost instead of ARWpost to post process the files 
and output Grib or GEMPAK files.  

Don

> On Apr 18, 2011, at 11:15 AM, Unidata IDV Support wrote:
> 
> > Hi Stefan-
> >
> > I'm not reading the IDV support regularly now, but happened to
> > notice this.  Could you send the .ctl file for the WRFPost output?
> >
> > Don Murray
> >
> >> Full Name: Stefan Cecelski
> >> Email Address: address@hidden
> >> Organization: University of Maryland
> >> Package Version:
> >> Operating System:
> >> Hardware:
> >> Description of problem:
> >>
> >> Hi all,
> >>
> >> I know you aren't fully supporting GrADS files in your nightly build,
> >> but I'd thought I'd give you some feedback on my experiences thus
> >> far. I
> >> create .dat/.ctl pairs of my WRF output using ARWpost processing.
> >> When
> >> opening the .ctl file, I see all the variables created by ARWpost and
> >> the derived variables that can be calculated by IDV in the field
> >> selector
> >> window. However, plotting derived variables by IDV results in an
> >> error,
> >> and variables processed through ARWpost have values that range
> >> between
> >> -2E39 and 2E39 and look like just 'noise' when plotted. The error
> >> for the IDV derived variables comes from IDV not being able to find
> >> variables needed for calculation. I think this is because ARWpost(or
> >> other post processing software) changes the variable name to some
> >> other
> >> convention. I have tried plotting many ARWpost generated variables,
> >> and all just look like noise with extremely large(or small) values on
> >> the order of E39 to E42(or E-39 ect).
> >>
> >> I would attach my .dat/.ctl pairs, but my files are all well over
> >> 1GB. I can try to create a small subset of data if you all would be
> >> interested. Attached is a text file showing the error from trying to
> >> create Theta-E using IDV from the data.
> >>
> >> Thanks!
> >>
> >> V/R,
> >>
> >> Stefan
> >>
> >>
> >
> >
> > Ticket Details
> > ===================
> > Ticket ID: LCA-261543
> > Department: Support IDV
> > Priority: Normal
> > Status: Open
> >
> 
> 
> 


Ticket Details
===================
Ticket ID: LCA-261543
Department: Support IDV
Priority: Normal
Status: Open