#! /usr/bin/env python
#
def r8_tand ( degrees ):

#*****************************************************************************80
#
## R8_TAND returns the tangent of an angle given in degrees.
#
#  Licensing:
#
#    This code is distributed under the GNU LGPL license.
#
#  Modified:
#
#    27 July 2014
#
#  Author:
#
#    John Burkardt
#
#  Parameters:
#
#    Input, real DEGREES, the angle in degrees.
#
#    Output, real VALUE, the tangent of the angle.
#
  import numpy as np

  radians = np.pi * ( degrees / 180.0 )

  value = np.sin ( radians ) / np.cos ( radians )

  return value

def r8_tand_test ( ):

#*****************************************************************************80
#
## R8_TAND_TEST tests R8_TAND.
#
#  Licensing:
#
#    This code is distributed under the GNU LGPL license. 
#
#  Modified:
#
#    12 January 2015
#
#  Author:
#
#    John Burkardt
#
  import platform

  print ( '' )
  print ( 'R8_TAND_TEST' )
  print ( '  Python version: %s' % ( platform.python_version ( ) ) )
  print ( '  R8_TAND computes the tangent of an angle' )
  print ( '  given in degrees.' )
  print ( '' )
  print ( '  ANGLE    R8_TAND(ANGLE)' )
  print ( '' )
 
  for i in range ( 0, 375, 15 ):
    angle = float ( i )
    if ( ( ( i + 90 ) % 180 ) == 0 ):
      print ( '  %8.2f    Undefined' % ( angle ) )
    else:
      print ( '  %8.2f  %14.6g' % ( angle, r8_tand ( angle ) ) )
#
#  Terminate.
#
  print ( '' )
  print ( 'R8_TAND_TEST' )
  print ( '  Normal end of execution.' )
  return

if ( __name__ == '__main__' ):
  from timestamp import timestamp
  timestamp ( )
  r8_tand_test ( )
  timestamp ( )