Boundary Conditions

Fixed Boundary Mean

Including Edge Values

A fixed boundary condition sets the edge values before an aggregate is calculated.

Program

Play the program to choose the boundary value and recompute the field mean.

fixed_boundary_mean.f90 
program fixed_boundary_mean_demo
    implicit none
    real :: field(5)
    real :: boundary_value
    real :: total
    real :: mean_value
    integer :: i

    field = [0.0, 2.0, 4.0, 6.0, 0.0]
    boundary_value = 
    field(1) = boundary_value
    field(5) = boundary_value
    total = 0.0
    do i = 1, 5
        total = total + field(i)
    end do
    mean_value = total / 5.0
    print '(F0.1, 1X, F0.1)', boundary_value, mean_value
end program fixed_boundary_mean_demo

program fixed_boundary_mean_demo
    implicit none
    real :: field(5)
    real :: boundary_value
    real :: total
    real :: mean_value
    integer :: i

    field = [0.0, 2.0, 4.0, 6.0, 0.0]
    boundary_value = 
    field(1) = boundary_value
    field(5) = boundary_value
    total = 0.0
    do i = 1, 5
        total = total + field(i)
    end do
    mean_value = total / 5.0
    print '(F0.1, 1X, F0.1)', boundary_value, mean_value
end program fixed_boundary_mean_demo

program fixed_boundary_mean_demo
    implicit none
    real :: field(5)
    real :: boundary_value
    real :: total
    real :: mean_value
    integer :: i

    field = [0.0, 2.0, 4.0, 6.0, 0.0]
    boundary_value = 
    field(1) = boundary_value
    field(5) = boundary_value
    total = 0.0
    do i = 1, 5
        total = total + field(i)
    end do
    mean_value = total / 5.0
    print '(F0.1, 1X, F0.1)', boundary_value, mean_value
end program fixed_boundary_mean_demo
fixed boundary The first and last field entries are assigned before the aggregate.
interior data Interior values stay unchanged while boundary values vary.
aggregate effect The mean includes both fixed boundary values and interior values.