Weighted Table Total - Modern Fortran Programming

A calculation table can pair values with weights and accumulate row contributions.
Program

Play the program to include more rows in the weighted total.
                            row_count
                            row_count = 2 (default)row_count = 1row_count = 3
                        

                            weighted_table_total.f90
                        
Replay: real traced execution (multi-file project)

                            program weighted_table_total_demo
    implicit none
    integer :: values(3)
    integer :: weights(3)
    integer :: row_count
    integer :: i
    integer :: total
    integer :: contribution

    values = [5, 7, 9]
    weights = [2, 3, 4]
    row_count = 2
    total = 0
    do i = 1, row_count
        contribution = values(i) * weights(i)
        total = total + contribution
    end do
    print '(I0, 1X, I0)', row_count, total
end program weighted_table_total_demo
program weighted_table_total_demo
    implicit none
    integer :: values(3)
    integer :: weights(3)
    integer :: row_count
    integer :: i
    integer :: total
    integer :: contribution

    values = [5, 7, 9]
    weights = [2, 3, 4]
    row_count = 1
    total = 0
    do i = 1, row_count
        contribution = values(i) * weights(i)
        total = total + contribution
    end do
    print '(I0, 1X, I0)', row_count, total
end program weighted_table_total_demo
program weighted_table_total_demo
    implicit none
    integer :: values(3)
    integer :: weights(3)
    integer :: row_count
    integer :: i
    integer :: total
    integer :: contribution

    values = [5, 7, 9]
    weights = [2, 3, 4]
    row_count = 3
    total = 0
    do i = 1, row_count
        contribution = values(i) * weights(i)
        total = total + contribution
    end do
    print '(I0, 1X, I0)', row_count, total
end program weighted_table_total_demo

                        
1values ← [5, 7, 9]⋯10values = [5, 7, 9]11weights = [2, 3, 4]⋯values this step[5, 7, 9]values
2weights ← [2, 3, 4]⋯10values = [5, 7, 9]11weights = [2, 3, 4]12row_count = 2⋯values this step[2, 3, 4]weights
3row_count ← 2⋯11weights = [2, 3, 4]12row_count = 213total = 0⋯values this step2row_count
4total ← 0⋯12row_count = 213total = 014do i = 1, row_count⋯values this step0total
5i ← 1⋯13total = 014do i = 1, row_count15    contribution = values(i) * weights(i)⋯values this step1i
6contribution ← 10⋯14do i = 1, row_count15    contribution = values(i) * weights(i)16    total = total + contribution⋯values this step10contribution5values(1)2weights(1)
7total ← 10⋯15    contribution = values(i) * weights(i)16    total = total + contribution17end do⋯values this step0 → 10total10contribution
8i ← 2⋯13total = 014do i = 1, row_count15    contribution = values(i) * weights(i)⋯values this step2i
9contribution ← 21⋯14do i = 1, row_count15    contribution = values(i) * weights(i)16    total = total + contribution⋯values this step21contribution7values(2)3weights(2)
10total ← 31⋯15    contribution = values(i) * weights(i)16    total = total + contribution17end do⋯values this step10 → 31total21contribution
11print '(I0, 1X, I0)', row_count, total⋯17    end do18    print '(I0, 1X, I0)', row_count, total19end program weighted_table_total_demooutput2 31values this step2row_count31total
1values ← [5, 7, 9]⋯10values = [5, 7, 9]11weights = [2, 3, 4]⋯values this step[5, 7, 9]values
2weights ← [2, 3, 4]⋯10values = [5, 7, 9]11weights = [2, 3, 4]12row_count = 1⋯values this step[2, 3, 4]weights
3row_count ← 1⋯11weights = [2, 3, 4]12row_count = 113total = 0⋯values this step1row_count
4total ← 0⋯12row_count = 113total = 014do i = 1, row_count⋯values this step0total
5i ← 1⋯13total = 014do i = 1, row_count15    contribution = values(i) * weights(i)⋯values this step1i
6contribution ← 10⋯14do i = 1, row_count15    contribution = values(i) * weights(i)16    total = total + contribution⋯values this step10contribution5values(1)2weights(1)
7total ← 10⋯15    contribution = values(i) * weights(i)16    total = total + contribution17end do⋯values this step0 → 10total10contribution
8print '(I0, 1X, I0)', row_count, total⋯17    end do18    print '(I0, 1X, I0)', row_count, total19end program weighted_table_total_demooutput1 10values this step1row_count10total
1values ← [5, 7, 9]⋯10values = [5, 7, 9]11weights = [2, 3, 4]⋯values this step[5, 7, 9]values
2weights ← [2, 3, 4]⋯10values = [5, 7, 9]11weights = [2, 3, 4]12row_count = 3⋯values this step[2, 3, 4]weights
3row_count ← 3⋯11weights = [2, 3, 4]12row_count = 313total = 0⋯values this step3row_count
4total ← 0⋯12row_count = 313total = 014do i = 1, row_count⋯values this step0total
5i ← 1⋯13total = 014do i = 1, row_count15    contribution = values(i) * weights(i)⋯values this step1i
6contribution ← 10⋯14do i = 1, row_count15    contribution = values(i) * weights(i)16    total = total + contribution⋯values this step10contribution5values(1)2weights(1)
7total ← 10⋯15    contribution = values(i) * weights(i)16    total = total + contribution17end do⋯values this step0 → 10total10contribution
8i ← 2⋯13total = 014do i = 1, row_count15    contribution = values(i) * weights(i)⋯values this step2i
9contribution ← 21⋯14do i = 1, row_count15    contribution = values(i) * weights(i)16    total = total + contribution⋯values this step21contribution7values(2)3weights(2)
10total ← 31⋯15    contribution = values(i) * weights(i)16    total = total + contribution17end do⋯values this step10 → 31total21contribution
11i ← 3⋯13total = 014do i = 1, row_count15    contribution = values(i) * weights(i)⋯values this step3i
12contribution ← 36⋯14do i = 1, row_count15    contribution = values(i) * weights(i)16    total = total + contribution⋯values this step36contribution9values(3)4weights(3)
13total ← 67⋯15    contribution = values(i) * weights(i)16    total = total + contribution17end do⋯values this step31 → 67total36contribution
14print '(I0, 1X, I0)', row_count, total⋯17    end do18    print '(I0, 1X, I0)', row_count, total19end program weighted_table_total_demooutput3 67values this step3row_count67total
paired columns `values(i)` and `weights(i)` are matching columns in the same row.
contribution Each row contribution is calculated before it is added to the total.
partial table `row_count` lets a calculation use only the active rows.