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Re: Sine and Cosine Accuracy
Richard Henderson wrote:
> On Thu, May 26, 2005 at 10:34:14AM -0400, Scott Robert Ladd wrote:
>
>> static const double range = PI; // * 2.0;
>> static const double incr = PI / 100.0;
>
>
> The trig insns fail with large numbers; an argument
> reduction loop is required with their use.
Yes, but within the defined mathematical ranges for sine and cosine --
[0, 2 * PI) -- the processor intrinsics are quite accurate.
Now, I can see a problem in signal processing or similar applications,
where you're working with continuous values over a large range, but it
seems to me that a simple application of fmod (via FPREM) solves that
problem nicely.
I've never quite understood the necessity for performing trig operations
on excessively large values, but perhaps my problem domain hasn't
included such applications.
..Scott