FORTRAN

integer gdllwdval, ier
ier = gdxywdval(gdid, spdvals, wdvals, uuin, vvin, x, y, n)
integer gdid, n
real spdvals(n), wdvals(n), uuin(*), vvin(*), x(n), y(n)

C

int c_gdlxydval(int gdid, float *spdvals, float *wdvals, float *uuin,  float *vvin,
                 float xt, float yn, int n)

gdllwdval does a bi-dimensional vector interpolation on the values contained in uuin and vvin, themselves defined on grid gdid, at selected lat/lon points. Interpolated values are returned in spdvals and wdvals, in meteorological wind speed and direction.

gdid

a valid grid identifier (returned by ezqkdef or ezgdef) that will be used as the source (input) grid.

spdvals, wdvals

Output interpolated winds, in grid coordinates based on gdid. There is 1:1 relationship with zvals and lat/lon; that is, interpolated values at point lat(1), lon(1) is zvals(1).

uuin, vvin

Input (source) winds. uuin and vvin are assumed to have the dimensions referred by gdid (the input grid).

lat

Stream of latitude points