Function msfnz

msfnz(eccent: number, sinphi: number, cosphi: number): number
Convienience function to compute msfnz(eccent, sinphi, cosphi)
Parameters
- eccent: number
  eccentricity
- sinphi: number
  sin of latitude
- cosphi: number
  cos of latitude
Returns number
- msfnz(eccent, sinphi, cosphi)