NAG Library Routine Document

x02ahf returns the largest positive argument for which the Fortran intrinsic functions SIN and COS return a result with some meaningful accuracy.

Fortran Interface

Function x02ahf ( x) Real (Kind=nag_wp) :: x02ahf Real (Kind=nag_wp), Intent (In) :: x

C Header Interface

#include nagmk26.h double  x02ahf_ ( double *x)

The trigonometric functions $\sin$ and $\cos$ supplied in some compiler run-time libraries do not return accurate results when their argument is large. Often the related accuracy of a result gets progressively worse as the argument gets larger. x02ahf gives a value beyond which the compiler run-time library returns results with no relative accuracy at all. Note that some run-time libraries do return accurate results for all arguments to $\sin$ and $\cos$.

None.

None.

None.

x02ahf is not threaded in any implementation.

None.

See Section 10 in x02ajf.