easydop853_test.f90

program easydop853_test

    use iso_fortran_env, only: wp => real64

    use easydop853_module

    implicit none

    procedure(deriv_func) :: fcn
    !! subroutine computing the value of \(dy/dx=f(x,y)\)
    real(wp), save :: x = 0.0_wp
    !! `x` value (input is initial value and output is final value)
    real(wp), save :: xend = 225000.0_wp
    !! endpoint of integration (final value of `x`)
    real(wp), dimension(6), save :: y = [1.0_wp, 0.0_wp, 0.0_wp, &
                                         0.0_wp, 1.0_wp, 0.0_wp]
    !! `y` value (input is initial value and output is final value)

    call easydop853(fcn, x, xend, y)

    print *, x
    print *, y

end program easydop853_test