预订演示
前页 后页

sindg

Circular sine of an angle in degrees.

SYNOPSIS:

double x, y, sindg();
y = sindg(x);

DESCRIPTION:

Range reduction is into intervals of 45 degrees. Two polynomial approximating functions are employed.
Between 0 and pi/4 the sine is approximated by:
     x  +  x**3 P(x**2).

Between pi/4 and pi/2 the cosine is represented as:
     1  -  x**2 P(x**2).

ACCURACY:
                      Relative error:
arithmetic   domain      # trials      peak         rms
    DEC       +-1000        3100      3.3e-17      9.0e-18
    IEEE      +-1000       30000      2.3e-16      5.6e-17

ERROR MESSAGES:

   message            condition        value returned
   total loss      x > 8.0e14 (DEC)         0.0
                   x > 1.0e14 (IEEE)