#! /usr/bin/env python
#
def bessel_j_spherical_values ( n_data ):

#*****************************************************************************80
#
## BESSEL_J_SPHERICAL_VALUES returns values of the Spherical Bessel function j.
#
#  Discussion:
#
#    In Mathematica, the function can be evaluated by:
#
#      Sqrt[Pi/(2*x)] * BesselJ[n+1/2,x]
#
#  Licensing:
#
#    This code is distributed under the GNU LGPL license.
#
#  Modified:
#
#    16 January 216
#
#  Author:
#
#    John Burkardt
#
#  Reference:
#
#    Milton Abramowitz, Irene Stegun,
#    Handbook of Mathematical Functions,
#    US Department of Commerce, 1964.
#
#    Stephen Wolfram,
#    The Mathematica Book,
#    Fourth Edition,
#    Wolfram Media / Cambridge University Press, 1999.
#
#  Parameters:
#
#    Input/output, integer N_DATA.  The user sets N_DATA to 0 before the
#    first call.  On each call, the routine increments N_DATA by 1, and
#    returns the corresponding data; when there is no more data, the
#    output value of N_DATA will be 0 again.
#
#    Output, integer N, the index of the function.
#
#    Output, real X, the argument of the function.
#
#    Output, real FX, the value of the function.
#
  import numpy as np

  n_max = 22

  fx_vec = np.array ( [ \
     0.8689780717709105E+00, \
     0.2776712616989048E+00, \
     0.05147914933043151E+00, \
     0.006743927971987495E+00, \
     0.0006838294584220406E+00, \
     0.00005658597917091951E+00, \
     3.955923765931341E-06, \
     2.394450910776484E-07, \
     1.277940110150618E-08, \
     6.099572379372921E-10, \
     2.633096568558721E-11, \
    -0.05440211108893698E+00, \
     0.07846694179875155E+00, \
     0.07794219362856245E+00, \
    -0.03949584498447032E+00, \
    -0.1055892851176917E+00, \
    -0.05553451162145218E+00, \
     0.04450132233409427E+00, \
     0.1133862306557747E+00, \
     0.1255780236495678E+00, \
     0.1000964095484906E+00, \
     0.06460515449256426E+00 ] )

  n_vec = np.array ( [ \
     0, \
     1, \
     2, \
     3, \
     4, \
     5, \
     6, \
     7, \
     8, \
     9, \
    10, \
     0, \
     1, \
     2, \
     3, \
     4, \
     5, \
     6, \
     7, \
     8, \
     9, \
    10 ] )

  x_vec = np.array ( [ \
     0.9050000000000000E+00, \
     0.9050000000000000E+00, \
     0.9050000000000000E+00, \
     0.9050000000000000E+00, \
     0.9050000000000000E+00, \
     0.9050000000000000E+00, \
     0.9050000000000000E+00, \
     0.9050000000000000E+00, \
     0.9050000000000000E+00, \
     0.9050000000000000E+00, \
     0.9050000000000000E+00, \
    10.00000000000000E+00, \
    10.00000000000000E+00, \
    10.00000000000000E+00, \
    10.00000000000000E+00, \
    10.00000000000000E+00, \
    10.00000000000000E+00, \
    10.00000000000000E+00, \
    10.00000000000000E+00, \
    10.00000000000000E+00, \
    10.00000000000000E+00, \
    10.00000000000000E+00 ] )

  if ( n_data < 0 ):
    n_data = 0

  if ( n_max <= n_data ):
    n_data = 0
    n = 0
    x = 0.0
    fx = 0.0
  else:
    n = n_vec[n_data]
    x = x_vec[n_data]
    fx = fx_vec[n_data]
    n_data = n_data + 1

  return n_data, n, x, fx

def bessel_j_spherical_values_test ( ):

#*****************************************************************************80
#
## BESSEL_J_SPHERICAL_VALUES_TEST tests BESSEL_J_SPHERICAL_VALUES.
#
#  Licensing:
#
#    This code is distributed under the GNU LGPL license.
#
#  Modified:
#
#    16 January 2016
#
#  Author:
#
#    John Burkardt
#
  print ( '' )
  print ( 'BESSEL_J_SPHERICAL_VALUES_TEST:' )
  print ( '  BESSEL_J_SPHERICAL_VALUES stores values of the spherical Bessel J function. of order N.' )
  print ( '' )
  print ( '     N      X        Spherical J(N,X)' )
  print ( '' )

  n_data = 0

  while ( True ):

    n_data, n, x, fx = bessel_j_spherical_values ( n_data )

    if ( n_data == 0 ):
      break

    print ( '  %2d  %12f  %24.16g' % ( n, x, fx ) )
#
#  Terminate.
#
  print ( '' )
  print ( 'BESSEL_J_SPHERICAL_VALUES_TEST:' )
  print ( '  Normal end of execution.' )
  return

if ( __name__ == '__main__' ):
  from timestamp import timestamp
  timestamp ( )
  bessel_j_spherical_values_test ( )
  timestamp ( )