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Re: Sine and Cosine Accuracy
>>>>> "Scott" == Scott Robert Ladd <scott.ladd@coyotegulch.com> writes:
Scott> 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.
Scott> Yes, but within the defined mathematical ranges for sine and
Scott> cosine -- [0, 2 * PI) -- the processor intrinsics are quite
Scott> accurate.
Huh? Sine and consine are mathematically defined for all finite
inputs.
Yes, normally the first step is to reduce the arguments to a small
range around zero and then do the series expansion after that, because
the series expansion convergest fastest near zero. But sin(100) is
certainly a valid call, even if not a common one.
paul