inline T asymptotic_bessel_j_large_x_2(T v, T x)
{
   // See A&S 9.2.19.
   BOOST_MATH_STD_USING
   // Get the phase and amplitude:
   T ampl = asymptotic_bessel_amplitude(v, x);
   T phase = asymptotic_bessel_phase_mx(v, x);
   BOOST_MATH_INSTRUMENT_VARIABLE(ampl);
   BOOST_MATH_INSTRUMENT_VARIABLE(phase);
   //
   // Calculate the sine of the phase, using
   // sine/cosine addition rules to factor in
   // the x - PI(v/2 + 1/4) term not added to the
   // phase when we calculated it.
   //
   BOOST_MATH_INSTRUMENT_CODE(cos(phase));
   BOOST_MATH_INSTRUMENT_CODE(cos(x));
   BOOST_MATH_INSTRUMENT_CODE(sin(phase));
   BOOST_MATH_INSTRUMENT_CODE(sin(x));
   T cx = cos(x);
   T sx = sin(x);
   T ci = cos_pi(v / 2 + 0.25f);
   T si = sin_pi(v / 2 + 0.25f);
   T sin_phase = cos(phase) * (cx * ci + sx * si) - sin(phase) * (sx * ci - cx * si);
   BOOST_MATH_INSTRUMENT_VARIABLE(sin_phase);
   return sin_phase * ampl;
}
示例#2
0
inline T asymptotic_bessel_j_large_x_2(T v, T x)
{
   // See A&S 9.2.19.
   BOOST_MATH_STD_USING
   // Get the phase and amplitude:
   T ampl = asymptotic_bessel_amplitude(v, x);
   T phase = asymptotic_bessel_phase_mx(v, x);
   //
   // Calculate the sine of the phase, using:
   // cos(x+p) = cos(x)cos(p) - sin(x)sin(p)
   //
   T sin_phase = cos(phase) * cos(x) - sin(phase) * sin(x);
   return sin_phase * ampl;
}