discmethod <- function ( f, a, b )

#*****************************************************************************80
#
## discmethod estimates a volume using the disc method.
#
#  Licensing:
#
#    Copyright 2016 James P. Howard, II
#
#    The computer code and data files on this web page are distributed under
#    https://opensource.org/licenses/BSD-2-Clause, the BSD-2-Clause license.
#
#  Modified:
#
#    10 March 2020
#
#  Author:
#
#    Original R code by James Howard;
#    Modifications by John Burkardt.
#
#  Reference:
#
#    James Howard,
#    Computational Methods for Numerical Analysis with R,
#    CRC Press, 2017,
#    ISBN13: 978-1-4987-2363-3.
#
{
  source ( "/home/burkardt/public_html/r_src/midpt/midpt.R" )  

  solid <- function ( x ) { return ( pi * ( f(x) )^2 ) }

  value = midpt ( solid, a, b )

  return ( value )
}