If the data are organized so that all of the longitudes and latitudes of a grid are listed, with the times and data values, then what you have done is almost correct. That is, say your data were on a 3x2 grid in X and Y, and 12 months in time, where lon runs 309 through 311 and lat is 45-46 degrees. If your data is arranged as follows,
lat lon month taux tauy
309.0 45.0 1 -4.940 -0.820
310.0 45.0 1 -4.599 -2.730
311.0 45.0 1 -4.767 -2.711
309.0 46.0 1 -4.860 -2.308
310.0 46.0 1 -6.219 -2.213
311.0 46.0 1 -6.191 -1.970
309.0 45.0 2 -4.940 -0.820
310.0 45.0 2 -4.599 -2.730
311.0 45.0 2 -4.767 -2.711
309.0 46.0 2 -4.860 -2.308
310.0 46.0 2 -6.219 -2.213
311.0 46.0 2 -6.191 -1.970
...
309.0 45.0 12 -4.940 -0.820
310.0 45.0 12 -4.599 -2.730
311.0 45.0 12 -4.767 -2.711
309.0 46.0 12 -4.860 -2.308
310.0 46.0 12 -6.219 -2.213
311.0 46.0 12 -6.191 -1.970
then commands like yours would read it correctly. You could use the longitude and latitude values in the file to define longitude and latitude axes, but Ferret does not do that automatically.
To plot month 6, you would need just
fill/L=6 taux
or
fill/T=6 taux
Ferret doesn't use the name of the axis to choose the time-step to plot, but instead the index value which is L on a time axis, or the coordinate value. In your case because you are using month-number, the time coordinate and the time index are the same. (If your data were in days, then months might be something like T=15, t=45, and so forth, with T representing the number of days to the middle of each month.)
-Ansley
On 7/1/2011 5:20 AM, Srinivas Chamarthi wrote:
I have a data set defined in 5 columns lon,lat, month (jan to dec in nos 1:12), taux, tauy
I wanted to plot the data for the month of june(ie t=6), it gives the error in time axis
my jnl file is as below
-----------------------------------------------------------------
let im=600 ! no of longitudes points (not longitude values)
let jm=375 ! no. of lalitude points (not latitude vales)
let tm=12 ! no. of month points
define axis/x=1:600:1 xindex
define axis/y=1:375:1 yindex
define axis/T=1:12:1 time
define grid/x=xindex/y=yindex/T=time xyt_grid
file/grid=xyt_grid/var="lon,lat,time,taux,tauy" velplot.dat ! for 3D
set variable/units=degrees_east lon
set variable/units=degrees_north lat
set variable/units="month" time
set variable/units="m2/s" taux
set variable/units="m2/s" tauy
set viewport ul
fill/time=6 taux,lon,lat
go land
set viewport ur
fill/time=6 tauy,lon,lat
go land
set viewport lr
vec/time=6 taux,tauy
go land
----------------------------------------------------
can some one correct me
thanks for ur time and help .. in advance.
with regards
CS
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