qpms/oldtests/bessel_precision/sagebesselgen.py

from __future__ import print_function

def printhankelrow(lMax, x, file=sys.stdout):
    print(lMax, N(x), end=' ', file=file);
    for l in range(lMax+1):
        print(N(spherical_hankel1(l,x)), end = ' ', file=file)
    print('', file=file)


def printbesselJrow(lMax, x, file=sys.stdout):
    print(lMax, N(x), end=' ', file=file);
    for l in range(lMax+1):
        print(N(spherical_bessel_J(l,x)), end = ' ', file=file)
    print('', file=file)


def printbesselYrow(lMax, x, file=sys.stdout):
    print(lMax, N(x), end=' ', file=file);
    for l in range(lMax+1):
        print(N(spherical_bessel_Y(l,x)), end = ' ', file=file)
    print('', file=file)


#cf DLMF 10.51.2

def printbesselDJrow(lMax, x, file=sys.stdout):
    print(lMax, N(x), end=' ', file=file);
    for l in range(lMax+1):
        print(N(-spherical_bessel_J(l+1,x)
            + l/x*spherical_bessel_J(l,x)), end = ' ', file=file)
    print('', file=file)


def printbesselDYrow(lMax, x, file=sys.stdout):
    print(lMax, N(x), end=' ', file=file);
    for l in range(lMax+1):
        print(N(-spherical_bessel_Y(l+1,x)
            + l/x*spherical_bessel_Y(l,x)), end = ' ', file=file)
    print('', file=file)


def ank(n, k):
    return factorial(n+k)/2**k/factorial(k)/factorial(n-k)

def genall(lMax):
    f = open('besselDJcases', 'w')
    for o in IntegerRange(1,100):
        printbesselDJrow(lMax, o, file=f)
        printbesselDJrow(lMax, 1/o, file=f)
        printbesselDJrow(lMax, o/sqrt(3), file=f)
    f = open('besselDYcases', 'w')
    for o in IntegerRange(1,100):
        printbesselDYrow(lMax, o, file=f)
        printbesselDYrow(lMax, 1/o, file=f)
        printbesselDYrow(lMax, o/sqrt(3), file=f)
    f = open('besselJcases', 'w')
    for o in IntegerRange(1,100):
        printbesselJrow(lMax, o, file=f)
        printbesselJrow(lMax, 1/o, file=f)
        printbesselJrow(lMax, o/sqrt(3), file=f)
    f = open('besselYcases', 'w')
    for o in IntegerRange(1,100):
        printbesselYrow(lMax, o, file=f)
        printbesselYrow(lMax, 1/o, file=f)
        printbesselYrow(lMax, o/sqrt(3), file=f)


import math
M_LN2 = math.log(2)

def ankf(n,k):
    n = float(n)
    k = float(k)
    return math.exp(math.lgamma(n+k+1) - k * M_LN2 - math.lgamma(k+1) - math.lgamma(n-k+1))

def ankrelerr(n,k):
    a = ank(n,k)
    b = ankf(n,k)
    return 2 * abs(a - b)/(abs(a)+abs(b))