This function is a grid-to-station interpolator. It creates "station" data result by sampling a gridded data set and interpolating to a given location. That location may be provided by specifying a longitude and a latitude, or by providing a station expression.
gr2stn(grid_expr, stn_expr, <-n>)
gr2stn(grid_expr, lon, lat, <-n>)
grid_expris a GrADS expression that gives a grid result. The interpolation will be done on this data. The
grid_exprmay be a 2-D grid that varies in X and Y, or a 1-D grid that varies in Z or T.
stn_expr is a GrADS
expression that gives a station data result. The interpolation will be
done to the station locations, the station data values are not used.
lon,lat may be used instead of
stn_expr to specify the location to which the
gridded data will be interpolated (see Usage Note #3.)
(Version 2.0.a6 or later) The
-n option was added to return the nearest neighbor to the station location
instead of the bi-linear interpolation of the four surrounding grid points.
grid_expris a 2-D grid that varies in X and Y, then
stn_exprshould also be a 2-D expression that has multiple stations in the lat/lon domain. The result will be a station data set, with values interpolated from
grid_exprto the station locations.
grid_expris a 1-D grid, then only Z or T can be the varying dimension. In this case,
stn_exprshould be an expression that has a single location, such as "temp(stid=kdca)". Alternatively, you may provide exact longitude and latitude values.
where file 1 is gridded data, and file 3 is station data. The result would display as differences at the station locations.
oacresfunction to do a quick analysis of the station values: