On Nov 2, 2009, at 11:01 AM, Chunk 1978 wrote:
i just came across some code, and i'm trying to understand why the
developer
chose to use the pow() function instead of simply multiplying as the
2nd
arguments are always 2. i'm certainly no mathematician, but if the
2nd
argument is going to be 2, why use pow()? is it just a matter of
taste?
why use this:
float dist = pow(red - r, 2) + pow(green - g, 2) + pow(blue - b, 2);
instead of:
float dist = ((red - r) * 2) + ((green - g) * 2) + ((blue - b) * 2);
_______________________________________________
Those two lines mean entirely different things. x * 2 != x ^ 2.
Consider x = 3. 3 * 2 = 6. 3 ^ 2 = 9.
If the author didn't want to use the pow function, he/she might
streamline by doing x * x, but it's possible the author just didn't
want to have to write all that out, and felt that using the pow
function was more immediately clear what was going on without having
to write or read much.
Luke
_______________________________________________
Cocoa-dev mailing list ([email protected])
Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com
Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com
This email sent to [email protected]
