Evaluate a real function expressed in real spherical harmonics at a single point.
value
= MakeGridPoint (cilm
, lat
, lon
, [lmax
, norm
, csphase
, dealloc
])
value
: float
: Value of the function at (lat
, lon
).
cilm
: float, dimension (2, lmaxin
+1, lmaxin
+1)
: The real spherical harmonic coefficients of the function. The coefficients C0lm
and C1lm
refer to the cosine (Clm
) and sine (Slm
) coefficients, respectively, with Clm=cilm[0,1,m]
and Slm=cilm[1,l,m]
.
lat
: float
: The latitude of the point in DEGREES.
lon
: float
: The longitude of the point in DEGREES.
lmax
: optional, integer, default = lmaxin
: The maximum spherical harmonic degree used in evaluating the function.
norm
: optional, integer, default = 1
: 1 (default) = Geodesy 4-pi normalized harmonics; 2 = Schmidt semi-normalized harmonics; 3 = unnormalized harmonics; 4 = orthonormal harmonics.
csphase
: optional, integer, default = 1
: 1 (default) = do not apply the Condon-Shortley phase factor to the associated Legendre functions; -1 = append the Condon-Shortley phase factor of (-1)^m to the associated Legendre functions.
dealloc
: optional, integer, default = 0
: 0 (default) = Save variables used in the external Legendre function calls. (1) Deallocate this memory at the end of the funcion call.
MakeGridPoint
will expand a function expressed in spherical harmonics at a single point. The input latitude and longitude are in degrees, and the maximum degree used in evaluating the function is the smaller of lmaxin
and lmax
. The employed spherical harmonic normalization and Condon-Shortley phase convention can be set by the optional arguments norm
and csphase
; if not set, the default is to use geodesy 4-pi normalized harmonics that exclude the Condon-Shortley phase of (-1)^m.
makegridpointc, makegriddh, makegriddhc, makegridglq, makegridglqc