Hi All,
Just a bit more between Mario and I about his data, which we thought
we'd pass on to finish this thread. It turned out that Mario had named
a variable T, which caused most of his trouble, but there was some
useful discussion of curviilnear grids as well.
If the lon,
lat temp are just one-dimensional lists of points, then the 3-argument
shade command can't use the curvilinear grid to plot the data. I'll
show more
about this at the end
of this message. To look at your data in Ferret try
these commands.
yes? USE
test2.cdf
yes? show data
yes? show grid lon
What
axis is the data on? If it's
on the X axis, look
at
some of the data,
yes? list/i=1:10
temp, lon, lat
Is
your variable named T? If so,
that could be
causing
confusion as Ferret expects T to represent
the
time coordinate of a variable. You
could either
change
the name of the variable when the data is
corrected,
or with ncdump and ncgen. Or, if you
really
want to use T, then it can be referenced by
putting it
in single quotes:
yes? list/i=1:10
'T', lon, lat
Ferret
expects curvilinear data to be on a 2 dimensional grid,
I x J, where at each i,j point you have
the
latitude and
longitude
point corresponding to the curvilinear grid, and
the value of the
data field. Here is some output from a Ferret session. The
variables
are GEOLON,
GEOLAT, and ZVAR. These are all on a 180x173 point
grid
with axes XAX (i=1 to 180) and YAX (j
= 1 to 173)
yes? use lonlat.nc
yes? show data
currently
SET data sets:
1> ./lonlat.nc
(default)
name
title I
J K L
GEOLON geographic
longitude 1:180 1:173 ... ...
GEOLAT geographic
latitude 1:180 1:173 ... ...
ZVAR variable
on the grid 1:180
1:173 ... ...
yes? show grid geolon
GRID GMZ1
name
axis # pts start end
XAX X 180 r 1 180
YAX Y 173 r
1 173
normal Z
normal T
! Visualize the lon,lat curvilinear grid
yes? set view upper
yes? plot/vs/sym=dot/j=140:173
geolon, geolat
! Shade plot of a variable on the grid
yes? set view lower
yes? shade/j=140:173 ztp,
geolon, geolat
Mario Germano wrote:
Hi everybody,
I am experiencing difficulties in inserting grid points in a cdf file (using
FORTRAN) because these points have all different lon-lat coordinates: they
are not uniformly distributed on an orthogonal grid, but rather on a rotated
grid.
Ideally I'd like to be able to insert points one by one using a syntax like:
insert_point(lon,lat,wind_speed, temperature,...)
I ignore if such a thing is possible.
Thanks in advance for answering my question.
Mario.