#*****************************************************************************80
#
## gd_test tests gd.
#
#  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:
#
#    15 March 2020
#
#  Author:
#
#    John Burkardt
#
cat ( date ( ), "\n" )
cat ( "\n" )
cat ( "gd_test\n" )
cat ( " ", version$version.string, "\n" )
cat ( "  gd seeks the minimum of a function using gradient descent.\n" )
cat ( "\n" )

source ( "/home/burkardt/public_html/r_src/gd/gd.R" )  

fp <- function ( x ) 
{
  dfdx1 <- 2.0 * x[1] - 2.0
  dfdx2 <- 8.0 * x[2] - 8.0
  return ( c ( dfdx1, dfdx2 ) )
}
x = c( 0.0, 0.0 ) 
h = 0.05
m = 5

value <- gd ( fp, x, h, m = m )
cat ( "  gd((x-1)^2+(y-2)^2,[0,0],0.05,m=5) = ", value, "\n" )

x = c( 0.0, 0.0 ) 
h = 0.05
m = 20

value <- gd ( fp, x, h, m = m )
cat ( "  gd((x-1)^2+(y-2)^2,[0,0],0.05,m=20) = ", value, "\n" )
#
#  Terminate.
#
cat ( "\n" )
cat ( "gd_test\n" )
cat ( "  Normal end of execution.\n" )
cat ( date ( ), "\n" )

quit ( )