Compute the index of a array of Legendre functions corresponding to degree l and angular order m.
index = PlmIndex (l, m)
index : integer
: Index of an array of associated Legendre functions corresponding to degree l and angular order m.
l : integer
: The spherical harmonic degree.
m : integer
: The angular order.
PlmIndex will calculate the index of an array of associated Legendre functions corresponding to degree l and angular order m. The input arrays are generated by routines such as PlmBar, PlmBar_d1, PlmSchmidt, PlmSchmidt_d1, PlmON, PlmON_d1, PLegendreA, and PLegendreA_d1. The array index in Python is equal to l*(l+1)/2+m.
plmbar, plmbar_d1, plmschmidt, plmschmidt_d1, plmon, plmon_d1, plegendrea, plegendrea_d1