Rounding Algorithms

dtmos writes "Clive Maxfield has an interesting article up on PL DesignLine cataloging most (all?) of the known rounding algorithms used in computer math. As he states, "...the mind soon boggles at the variety and intricacies of the rounding algorithms that may be used for different applications ... round-up, round-down, round-toward-nearest, arithmetic rounding, round-half-up, round-half-down, round-half-even, round-half-odd, round-toward-zero, round-away-from-zero, round-ceiling, round-floor, truncation (chopping), round-alternate, and round-random (stochastic rounding), to name but a few." It's a good read, especially if you *think* you know what your programs are doing."

Comments

Computer games should use floor(x+rand())

[RedLaggedTeut]

Computer games should round randomly.

This means that every little bonus that the player gets might have an impact on the integer result. Example: phaos.

The "other" neat thing is that the expected value of
floor(x+rand()) == x
with 0.0=0.0