Hi Robert,
Your data is on curvilinear grids? It looks like at least the first
is.
We have in development a project to make all of this more seamless;
and at the same time implement the much-faster code from ESMF (Earth
System Modeling Framework). This work is scheduled to be finished
in the next several months.
Meanwhile, you might be able to use one of the SAMPLEXY_CURV
functions, picking out points from one grid and populating another.
See
yes? show function samplexy_curv*
There are also a pair of functions for mapping a curvilinear grid to
a rectilinear one,
yes? show function curv_to_rect*
CURV_TO_RECT(V,mapping)
Apply mapping to regrid from curvilinear to rectangular grid
V: Variable to regrid, on curvilinear grid V(x,y,z,t,e,f)
mapping: mapping computed by curv_to_rect_MAP
CURV_TO_RECT_MAP(lon_in,lat_in,grid_out,radius)
Compute mapping for regridding: curvilinear to rectangular
grid.
lon_in: Source grid longitudes (2-D) (degrees)
lat_in: Source grid latitudes (2-D) (degrees)
grid_out: Any variable on destination Longitude-Latitude grid,
Lon and Lat (degrees)
radius: Source points falling within radius are included in
mapping to destination point (degrees)
and vice versa,
RECT_TO_CURV(V,lon_bounds_out,lat_bounds_out,missing_allowed)
Regrid from rectangular to curvilinear grid
V: variable V(x,y,z,t,e,f) on rectilinear grid
lon_bounds_out: Destination curvilinear grid longitude
bounds(2-D) (degrees)
lat_bounds_out: Destination curvilinear grid latitude
bounds(2-D) (degrees)
missing_allowed: number of missing values allowed in four
surrounding source cells: 0 to 3
Best,
Ansley
On 11/10/2015 4:35 PM, Osinski, Robert
FORNATL, PL wrote:
Ansley, Paulo,
thank you very much for yours prompt answers but it wasn't
exactly what I need. I've studied ferret documentation before I
asked my question to the mailing-list but have not found answer.
My problem, in other words, is that I have satellite ice
concentration on grid 1280x720 (x=1:1280:1/y=1:720:1) and
modeled ice concentration on grid 5120x2880
(x=1:5120:1/y=1:2880:1) (see attached figures).
I want to draw satellite ice concentration on modeled ice. What
I know is that every fourth fine resolution grid point is in the
same place as coarse grid point. So for instance coarse
resolution value of concentration of x=10/y=10 should be at fine
resolution grid x=40/y=40, but there is no value for x=39/y=39
(interpolation is needed) and so on,
Thanks in advance,
Robert
Hi Robert,
This is a one-line command in Ferret. You have several
options for the regridding transformation; by default it's a
linear interpolation.
Perhaps the best thing to point you to is the regridding
demo. From the Ferret command line,
yes? go regridding_demo
The command window has description and comments along with
the Ferret commands; and you'll get plots showing what is
going on.
If you're a new user, welcome! I'd suggest exploring this
page,
http://ferret.pmel.noaa.gov/Ferret/documentation/ferret-tutorials
Ansley
On 11/10/2015 2:56 AM, Osinski,
Robert FORNATL, PL wrote:
Dear ferreters,
I need your help in interpolating and drawing two
datasets. The first data set is on coarse grid
x=1:1280:1/y=1:720:1 and the second on fine one
x=1:5120:1/y=1:2880:1. Each 4th grid point in the fine
grid is the same as in coarse resolution grid in space
so
coarse res. grid point fine res. grid point
(1,1) (4,4)
(1,2) (4,8)
(2,2) (8,8)
.....
I need to draw variable which is defined on coarse grid,
on fine grid. Obviously there will be "empty" grid
points on fine grid so it should be interpolate,
Thanks in advance,
Robert Osinski
NPS,
Monterey, CA
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