accumulate

alm= accumulate(n, f, mesh, rcap, rtrack, pts, dylm, flux, nrpp)
Do N batches (approximately rays_per_batch each, default 13000) of
rays from file F, MESH = hydra_mesh(F), analyzing the symmetry of
a capsule of radius RCAP (all rays tangent to this sphere),
tracing the rays only down to radius RTRACK (>1.001*RCAP).
This routine is designed to be called several times successively
to get better statistics. PTS, DYLM, FLUX, and NRPP are all updated.
PTS = unit vectors in directions of points on capsule surface
defaults to bucky(3,1): 1280 points with an intrinsic
fidelity of about 1% out to l=12
use bucky(4,1,domega), dylm= get_ylm(pts,lmax,list)*domega(,..)
to get 5120 points and intrinsic fidelity of about 0.2% at l=12
DYLM = ylm*domega for PTS
FLUX = accumulated flux at each of PTS; units are power/area
NRPP = accumulated number of rays per point of capsule surface
ALM = 91 coefficients of Ylm up to l=12 corresponding to FLUX
l= [0, 1,1, 2,2,2, 3,3,3,3, 4,4,4,4,4, ...]
m= [0, 0,1, 0,1,2, 0,1,2,3, 0,1,2,3,4, ...]
interpreted function, defined at i/ylmdec.i line 158
