program main !*****************************************************************************80 ! !! roots_rc_test() tests roots_rc(). ! ! Licensing: ! ! This code is distributed under the MIT license. ! ! Modified: ! ! 04 December 2016 ! ! Author: ! ! John Burkardt ! implicit none integer, parameter :: rk = kind ( 1.0D+00 ) integer, parameter :: n = 4 real ( kind = rk ) ferr real ( kind = rk ) fx(n) integer it integer, parameter :: it_max = 30 real ( kind = rk ) q(2*n+2,n+2) real ( kind = rk ) x(n) real ( kind = rk ) xnew(n) call timestamp ( ) write ( *, '(a)' ) ' ' write ( *, '(a)' ) 'roots_rc_test():' write ( *, '(a)' ) ' FORTRAN90 version' write ( *, '(a)' ) ' Test ROOTS_RC().' write ( *, '(a)' ) ' ' write ( *, '(a)' ) ' FERR X' write ( *, '(a)' ) ' ' ! ! Initialization. ! q(1:2*n+2,1:n+2) = 0.0D+00 xnew(1) = 1.2D+00 xnew(2:n) = 1.0D+00 it = 0 do x(1:n) = xnew(1:n) fx(1) = 1.0D+00 - x(1) fx(2:n) = 10.0D+00 * ( x(2:n) - x(1:n-1)**2 ) if ( it == 0 ) then write ( *, '(2x,14x,5(2x,g14.6))' ) x(1:n) else write ( *, '(2x,g14.6,5(2x,g14.6))' ) ferr, x(1:n) end if call roots_rc ( n, x, fx, ferr, xnew, q ) if ( ferr < 1.0D-07 ) then write ( *, '(a)' ) ' ' write ( *, '(a)' ) ' Sum of |f(x)| less than tolerance.' exit end if if ( it_max < it ) then write ( *, '(a)' ) ' ' write ( *, '(a)' ) ' Too many iterations!' exit end if it = it + 1 end do ! ! Terminate. ! write ( *, '(a)' ) ' ' write ( *, '(a)' ) 'ROOTS_RC_TEST:' write ( *, '(a)' ) ' Normal end of execution.' write ( *, '(a)' ) ' ' call timestamp ( ) stop 0 end