glqgridcoord(1)

GLQGridCoord

Compute the latitude and longitude coordinates used in Gauss-Legendre quadrature grids.

Usage

call GLQGridCoord (latglq, longlq, lmax, nlat, nlong, extend, exitstatus)

Parameters

latglq : output, real(dp), dimension (lmax+1)
    The latitude coordinates of a Gauss-Legendred quadrature grid in degrees.

longlq : output, real(dp), dimension (nlong)
    The longitude coordinates of a Gauss-Legendre quadrature grid in degrees, dimensioned as (2*lmax+1) when extend is 0 or (2*lmax+2) when extend is 1.

lmax : input, integer(int32)
    The maximum spherical harmonic degree that will be integrated exactly by Gauss-Legendre quadrature.

nlat : output, integer(int32)
    The number of samples in latitude.

nlong : output, integer(int32)
    The number of samples in longitude.

extend : input, optional, integer(int32), default = 0
    If 1, include 360 E longitude.

exitstatus : output, optional, integer(int32)
    If present, instead of executing a STOP when an error is encountered, the variable exitstatus will be returned describing the error. 0 = No errors; 1 = Improper dimensions of input array; 2 = Improper bounds for input variable; 3 = Error allocating memory; 4 = File IO error.

Description

GLQGridCoord will compute the latitude and longitude coordinates that are used in Gauss-Legendre quadrature grids for performing spherical harmonic transforms and reconstructions. The latitudinal nodes correspond to the zeros of the Legendre polynomial of degree lmax+1, and the longitudinal nodes are equally spaced with an interval of 360/(2*lmax+1) degrees.

See also

shglq, shexpandglq, makegridglq, shexpandglqc, makegridglqc, preglq