set verbose off
clear

scalar ROW = 10000
scalar COL = 20
scalar BLOCK_size = 2000
scalar BLOCK_start = 115
scalar LOOP = 600

matrix A = mnormal(ROW, COL)
matrix B = zeros(ROW, COL)

set stopwatch

loop LOOP --quiet
    loop i=1..BLOCK_size --quiet
        loop j=1..COL --quiet
            B[BLOCK_start - 1 + i, j] = A[BLOCK_start - 1 + i, j]
        endloop
    endloop
endloop
t1 = $stopwatch
n_add_sub = BLOCK_size * COL * 2 * 2
printf "loop 1:  %.4f (add/sub = %d)\n", t1, n_add_sub

set stopwatch
loop LOOP --quiet
    loop i=0..BLOCK_size-1 --quiet
        loop j=1..COL --quiet
            B[BLOCK_start + i, j] = A[BLOCK_start + i, j]
        endloop
    endloop
endloop
t2 = $stopwatch
n_add_sub = BLOCK_size * COL * 2 * 1
printf "loop 2:  %.4f (add/sub = %d)\n", t2, n_add_sub

loop LOOP --quiet
    loop i=1..BLOCK_size --quiet
        loop j=1..COL --quiet
            k = BLOCK_start - 1 + i
            B[k,j] = A[k,j]
        endloop
    endloop
endloop
t3 = $stopwatch
n_add_sub = BLOCK_size * COL * 2
printf "loop 3:  %.4f (add/sub = %d)\n", t3, n_add_sub

set stopwatch
loop LOOP --quiet
    loop i=0..BLOCK_size-1 --quiet
        loop j=1..COL --quiet
            k = BLOCK_start + i
            B[k,j] = A[k,j]
        endloop
    endloop
endloop
t4 = $stopwatch
n_add_sub = 1 + BLOCK_size * COL
printf "loop 4:  %.4f (add/sub = %d)\n", t4, n_add_sub

set stopwatch
loop LOOP --quiet
    loop i=0..BLOCK_size-1 --quiet
        k = BLOCK_start + i
        loop j=1..COL --quiet
            B[k,j] = A[k,j]
        endloop
    endloop
endloop
t4a = $stopwatch
n_add_sub = 1 + BLOCK_size
printf "loop 4a: %.4f (add/sub = %d)\n", t4a, n_add_sub


loop LOOP --quiet
    loop i=BLOCK_start..BLOCK_start-1+BLOCK_size --quiet
        loop j=1..COL --quiet
            B[i,j] = A[i,j]
        endloop
    endloop
endloop
t5 = $stopwatch
n_add_sub = 2
printf "loop 5:  %.4f (add/sub = %d)\n", t5, n_add_sub

loop LOOP --quiet
    imin = BLOCK_start
    imax = BLOCK_start-1+BLOCK_size
    loop j=1..COL --quiet
        B[imin:imax, j] = A[imin:imax, j]
    endloop
endloop
t6 = $stopwatch
n_add_sub = 2
printf "loop 6:  %.4f (add/sub = %d; column chunks)\n", t6, n_add_sub