#!/usr/bin/env python
#
def r8_sech ( x ):

#*****************************************************************************80
#
## R8_SECH evaluates the hyperbolic secant, while avoiding COSH overflow.
#
#  Licensing:
#
#    This code is distributed under the GNU LGPL license.
#
#  Modified:
#
#    25 July 2014
#
#  Author:
#
#    John Burkardt
#
#  Parameters:
#
#    Input, real X, the argument of the function.
#
#    Output, real R8_SECH, the value of the function.
#
  from math import cosh

  log_huge = 80.0

  if ( log_huge < abs ( x ) ):
    value = 0.0
  else
    value = 1.0 / cosh ( x )

  return value