Spherical wedge basis

[csskene]

Hi It would be nice for there to be a spherical wedge basis that can solve for a subset of wavenumbers in phi. For example, instead of having wavenumbers m in phi as [...,-4,-3,-2,-1,0,1,2,3,4,...], as in a shell basis, the spherical wedge basis would solve for [...-2m_c,-m_c,0,m_c,2m_c,...] where m_c is provided. This would be useful in providing a reduced model for some systems of equations that behave like this. Thanks, Calum