Re: why use pow(x, 2)?
Re: why use pow(x, 2)?
- Subject: Re: why use pow(x, 2)?
- From: Ed Wynne <email@hidden>
- Date: Mon, 2 Nov 2009 14:25:42 -0500
On Mon, Nov 2, 2009 at 2:07 PM, Jens Alfke <email@hidden> wrote:
On Nov 2, 2009, at 11:01 AM, Chunk 1978 wrote:
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);
Um, "*" is multiplication, not exponentiation. Maybe you're thinking
of the
"**" operator found in some languages, though not in C :)
That said, the original question is a good one. Using x*x instead of
pow(x,2)
would be quite a bit faster, so except for clarity reasons, there
isn't a good
reason to use pow() in that case.
-Ed
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