Convert a three-dimensional array of real spherical harmonic coefficients to a 1-dimensional indexed vector.

## Usage

vector = SHCilmToVector (cilm, [lmax])

## Returns

vector : float, dimension ( (lmax+1)**2 )
The indexed output real spherical harmonic coefficients.

## Parameters

cilm : float, dimension (2, lmaxin+1, lmaxin+1)
The input real spherical harmonic coefficients.
lmax : optional, integer, default = lmaxin
The maximum degree of the output coefficients to convert.

## Description

SHCilmToVector will convert a three-dimensional array of real spherical harmonic coefficients to a 1-dimensional indexed array. The degree l, order m, and i (1 for cosine, 2 for sine) corresponds to the index l**2+(i-1)*l+m.