#! /usr/bin/env python
#
def disk_area ( center, r ):

#*****************************************************************************80
#
## DISK_AREA returns the area of a general disk.
#
#  Licensing:
#
#    This code is distributed under the GNU LGPL license. 
#
#  Modified:
#
#    05 July 2018
#
#  Author:
#
#    John Burkardt
#
#  Parameters:
#
#    Input, real CENTER(2), the center of the disk. 
#    This information is not needed for the area calculation.
#
#    Input, real R, the radius of the disk.
#
#    Output, real AREA, the area of the unit disk.
#
  import numpy as np

  value = np.pi * r * r

  return value

def disk_area_test ( ):

#*****************************************************************************80
#
## DISK_AREA tests DISK_AREA.
#
#  Licensing:
#
#    This code is distributed under the GNU LGPL license.
#
#  Modified:
#
#    05 July 2018
#
#  Author:
#
#    John Burkardt
#
  import numpy as np
  import platform
  from r8vec_uniform_01 import r8vec_uniform_01

  print ( '' )
  print ( 'DISK_AREA_TEST' )
  print ( '  Python version: %s' % ( platform.python_version ( ) ) )
  print ( '  DISK_AREA returns the area of the unit disk.' )

  seed = 123456789
  center = np.zeros ( 2 )

  print ( '' )
  print ( '  (   CX        CY     )    R          Area' )
  print ( '' )

  for i in range ( 0, 10 ):
    data, seed = r8vec_uniform_01 ( 3, seed )
    center[0] = 10.0 * data[0] - 5.0
    center[1] = 10.0 * data[1] - 5.0
    r = data[2]
    area = disk_area ( center, r )
    print ( '  (%9.6f,%9.6f)  %9.6f  %9.6f' \
      % ( center[0], center[1], r, area ) )
#
#  Terminate.
#
  print ( '' )
  print ( 'DISK_AREA_TEST' )
  print ( '  Normal end of execution.' )
  return

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