Re: PLOT command ambiguous coordinates on T axis

[Steve Knox <stevek@xxxxxxxxxxxxxxxxxx>]

Ansley Manke wrote:

> Hi Steve,
> It's not an error, but an informational message, generated when
> Ferret reconciles the grids from the two variables to see if the
> variables can be compared.  Once this has been done successfully,
> Ferret keeps track of the information about how the grids were
> "merged", and so the message isn't issued on the subsequent commands
> that use the same grids.
>
> Ansley Manke
>
> Steve Knox wrote:
>
> > Why do I get the error on the first plot command but not when I simply
> > repeat the command?
> > Any insights would be greatly appreciated.
> >
> > ferret -gif
> >         NOAA/PMEL TMAP
> >         FERRET v5.50 (64bit CDF-No DODS)
> >         Solaris 5.8 - 01/23/03
> >         30-Jan-03 11:38
> >
> > yes? use ncepM1979
> > yes? use ncepM1980
> > yes? plot/l=1:12 tmax[D=1,y=30:40@ave,x=-120:-60@ave]-tmax[d=2,y=30:40@ave,x=-120:-60@ave]
> >  *** NOTE: Ambiguous coordinates on T axis: TMAX[D=1,Y=30:40@AVE,X=-120:-60@AVE]-TMAX[D=2Y=30:40@AVE,X=-120:-60@AVE]
> > yes? plot/l=1:12 tmax[D=1,y=30:40@ave,x=-120:-60@ave]-tmax[d=2,y=30:40@ave,x=-120:-60@ave]
> > yes? frame/file=d.gif
> >
> > The generated gif is ok.
> >
> > Steve Knox
> > NREL
> > Colorado State University
>
> --
> Ansley Manke  Pacific Marine Environmental Laboratory  Seattle WA  (206)526-6246

Thanks for your reply. To avoid this informative message should I be setting up the time axis before ferret tries to
reconcile
the grids?
Also, shouldn't the following statements generate the same results?
yes? list/l=1 tmax[d=1,y=40.25,x=-105.75]
             VARIABLE : TMAX (degrees C)
             FILENAME : ncepM1979.cdf
             LONGITUDE: 105W(-105)
             LATITUDE : 41N
             TIME     : 31-JAN-1979 10:29
         -6.784
If the lower lat = upper lat I get this:
yes? list/l=1 tmax[d=1,y=40.25:40.25@ave,x=-105.75:-105.75@ave]
             VARIABLE : TMAX (degrees C)
             FILENAME : ncepM1979.cdf
             LONGITUDE: 105W(-105) (XY ave)
             LATITUDE : 41N (XY ave)
             TIME     : 31-JAN-1979 10:29
        .... (should be -6.784)
If I leave off the ave transformation on the latitude it computes the ave correctly:
yes? list/l=1 tmax[d=1,y=40.25,x=-105.75:-105.75@ave]
             VARIABLE : TMAX (degrees C)
             FILENAME : ncepM1979.cdf
             LONGITUDE: 105W(-105) (averaged)
             LATITUDE : 41N
             TIME     : 31-JAN-1979 10:29
         -6.784

Steve