DIM zero3d(2)  'some example vectors
zero3d(0) = 0!: zero3d(1) = 0!: zero3d(2) = 0!
DIM zero5d(4)
zero5d(0) = 0!: zero5d(1) = 0!: zero5d(2) = 0!: zero5d(3) = 0!: zero5d(4) = 0!
DIM x(2): x(0) = 1!: x(1) = 0!: x(2) = 0!
DIM y(2): y(0) = 0!: y(1) = 1!: y(2) = 0!
DIM z(2): z(0) = 0!: z(1) = 0!: z(2) = 1!
DIM q(2): q(0) = 1!: q(1) = 1!: q(2) = 3.14159
DIM r(2): r(0) = -1!: r(1) = 2.618033989#: r(2) = 3!

PRINT " q dot r           = "; dot(q(), r())
PRINT " zero3d dot zero5d = "; dot(zero3d(), zero5d())
PRINT " zero3d dot x      = "; dot(zero3d(), x())
PRINT " z dot z           = "; dot(z(), z())
PRINT " y dot z           = "; dot(y(), z())

FUNCTION dot (a(), b())
    IF UBOUND(a) <> UBOUND(b) THEN dot = 0

    dp = 0!
    FOR i = 0 TO UBOUND(a)
        dp = dp + (a(i) * b(i))
    NEXT i
    dot = dp
END FUNCTION