SUBROUTINE GAUSS8 (nracp, RACP, PG, SIA, RAD, PGGSIN2,
SINM1, SINM2, SIN2)
ARGUMENTS
OUT
RACP(NRACP) Legendre polynomial roots
=sin(Gaus. lat.)
=cos(Gaus. colat.) real*8
PG(NRACP) corresponding Gaussian weights real*8
SIA(NRACP) sin(Gaus. colat.)=cos(Gaus. lat.) real*8
RAD(NRACP) Gaus. colat. in radians real*8
PGSSIN2(NRACP) PG/(sin(Gaus. colat.))**2 real*8
SINM1(NRACP) (sin(Gaus. colat.))**-1 real*8
SINM2(NRACP) (sin(Gaus. colat.))**-2 real*8
SIN2(NRACP) (sin(Gaus. colat.))**2 real*8
IN
NRACP number of positive roots of the
Legendre polynomial integer
DESCRIPTION
Computes the NRACP positive roots of the (2*NRACP)th-order Legendre polynomial. Same as gauss except that it uses real*8 instead of real*4.
EXAMPLE
Number 1
NOTES
All the NRACP roots are anti-symmetric relative to
equator(pi/2), being positive between colatitude 0 and pi/2.
After using an asymptotic formula to obtain an approximation
of the gaussian colatitudes, a Newton's method is employed to
gain precision, then Gauss weights and other functions
are calculated.
Notice that sin(lat.)=cos(colat.) where colat.=90-lat.
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