Precompute the weights and nodes used in the Gauss-Legendre quadrature based spherical harmonics routines.

## Usage

zero, w = SHGLQ (lmax)

## Returns

zero : float, dimension (lmax+1)
The nodes used in the Gauss-Legendre quadrature over latitude, determined from a call to PreGLQ.
w : float, dimension (lmax+1)
The weights used in the Gauss-Legendre quadrature over latitude, determined from a call to PreGLQ.

## Parameters

lmax : integer
The maximum spherical harmonic degree of the coefficients to be calculated in the Gauss-Legendre quadrature based spherical harmonic transform routines.

## Description

SHGLQ will calculate the weights and zeros used in the Gauss-Legendre quadrature based spherical harmonic routines SHExpandGLQ, MakeGridGLQ, SHExpandGLQC, and MakeGridGLQC.