Interpolation/
compute_fromirr_bilinear_weigaddr.pro
compute the weight and address needed to interpolate data from
an "irregular 2D grid" (defined as a grid made of quadrilateral cells)
to any grid using the bilinear method
compute_fromirr_bilinear_weigaddr
Interpolation
compute_fromirr_bilinear_weigaddr, olonin, olat, omsk, alonin, alat, amsk, weig, addr
Parameters
olonin
in
required
longitude of the input data
olat
in
required
latitude of the input data
omsk
in
required
land/sea mask of the input data
alonin
in
required
longitude of the output data
alat
in
required
latitude of the output data
amsk
in
required
land/sea mask of the output data
weig
out
addr
out
2D arrays, weig and addr are the weight and addresses used to
perform the interpolation:
dataout = total(weig*datain[addr], 1)
dataout = reform(dataout, jpia, jpja, /over)
Version history
Version
$Id: compute_fromirr_bilinear_weigaddr.pro 157 2006-08-21 09:01:50Z navarro $
History
June 2006: Sebastien Masson (smasson@lodyc.jussieu.fr)
Known issues
Restrictions
- the input grid must be an "irregular 2D grid", defined as a grid made
of quadrilateral cells which corners positions are defined with olonin and olat
- We supposed the data are located on a sphere, with a periodicity along
the longitude
- to perform the bilinear interpolation within quadrilateral cells, we
first morph the cell into a square cell and then compute the bilinear
interpolation.
- if some corners of the cell are land points, their weight is set to 0
and the weight is redistributed on the remaining "water" corners
- points located out of the southern and northern boundaries or in cells
containing only land points are set the the same value as their closest neighbor l
Produced by IDLdoc 2.0 on Tue Aug 29 14:49:14 2006.
