# PL Routines for the Spherical Solver

The section gives detailed description of spherical PL routines, their syntax, parameters and values they return. All flavors of the same routine, namely, double-precision and single-precision, periodic (having names ending in “p”) and non-periodic (having names ending in “np”), are described together.

These PL routines also call the Intel MKL FFT interface (described in FFT Functions), which enhances performance of the routines.

- ?_init_sph_p/?_init_sph_np
  Initializes basic data structures of the Fast periodic and non-periodic Helmholtz Solver on a sphere.
- ?_commit_sph_p/?_commit_sph_np
  Checks consistency and correctness of user's data as well as initializes certain data structures required to solve periodic/non-periodic Helmholtz problem on a sphere.
- ?_sph_p/?_sph_np
  Computes the solution of a spherical Helmholtz problem specified by the parameters.
- free_sph_p/free_sph_np
  Cleans the memory allocated for the data structures used by the FFT interface.

Parent topic: Poisson Library Routines