Re: Error in LONITUDE axis

[Jonathan Callahan <callahan@xxxxxxxxxxxxx>]

Robin,

This sounds like a problem with the definition of longitude as a
"modulo" axis.  We've seen this a bunch with datasets from NOAA/CDC
which do not specify the "modulo" attribute on their longitude axes. 
The version of Ferret you are running doesn't make an axis modulo unless
this attribute is present.  The most recent version of Ferret does.

You can solve your problem by adding a ferret property in your xml
description of this variable:

<properties>
 <ferret>
  <init_script>init_modulo_x</init_script>
 </ferret>
</properties>


The script (and some other useful ones) are described here:

  http://ferret.wrc.noaa.gov/Ferret/LAS/FAQ/initializing_data.htm


-- Jon


Robin Kovach wrote:
> 
> Hi all,
> 
> I've been getting an error that I cannot seem to find the reason for...
> 
> I have a data set on a one-degree regular grid (360X180).
> The error is:
> 
> Adding an acceptable error string: "*** NOTE: ".
>         NOAA/PMEL TMAP
>         Program FERRET
>         Version 5.22 - 07/27/00
>         22-Apr-02 12:06
> 
> yes? cancel mode verify
> yes? cancel mode interp
> yes? canc data/all
> yes? go std_initialize "/modcom/kovach/NCEP_SW/NCEP_SW" "1" "1" "ShortWaveRad"
> yes? set axis/modulo `ShortWaveRad,return=xaxis`
> yes? set region/x="180":"540"/y="-90.0":"89.0"/k=1/t="15-Jan-1948":"15-Jan-1948"
> yes? set win/size=0.5
> yes? set win/asp=0.745833333333333
> yes? GO "/tmp/lasgo259091454162.jnl"
> 
> The LAT is correct which ranges from -90 to 90. But somehow it is reading the
> LON range wrong (it should be -180 to 180) but LAS (or Ferret) seems to be
> reading set region/x="180":"540". I have the same data set up and .xml file set
> up for another data set that works fine. I can't find any difference between the
> two data sets that would cause this error.
> 
> LAS site: http://nsipp.gsfc.nasa.gov/las/
> Working Data Set: NCEP Winds Monthly Data
> Failing Data Set: NCEP Short Wave Radiation Monthly Data
> 
> The NetCDF files for both data sets have exactly the same LON and LAT values and
> attributes.
> 
> Has anyone seen this error before or have any suggestions on what I can try.
> I've also tried switching the LON range to 0 to 360 but the error is still the
> same.
> 
> Thank you,
> 
> Robin Kovach
> kovach@mohawk.gsfc.nasa.gov