Lines Matching defs:j0
33 static char sccsid[] = "@(#)j0.c 8.2 (Berkeley) 11/30/93";
67 /* double j0(double x), y0(double x)
69 * Method -- j0(x):
70 * 1. For tiny x, we use j0(x) = 1 - x^2/4 + x^4/64 - ...
71 * 2. Reduce x to |x| since j0(x)=j0(-x), and
73 * j0(x) = 1-z/4+ z^2*R0/S0, where z = x*x;
74 * (precision: |j0-1+z/4-z^2R0/S0 |<2**-63.67 )
76 * j0(x) = sqrt(2/(pi*x))*(p0(x)*cos(x0)-q0(x)*sin(x0))
88 * j0(nan)= nan
89 * j0(0) = 1
90 * j0(inf) = 0
95 * y0(x) = 2/pi*(j0(x)*(ln(x/2)+Euler) + x^2/4 - ...)
96 * therefore y0(x)-2/pi*j0(x)*ln(x) is an even function.
98 * y0(x) = U(z)/V(z) + (2/pi)*(j0(x)*ln(x)), z= x^2
103 * Note: For tiny x, U/V = u0 and j0(x)~1, hence
142 j0(double x)
165 * j0(x) = 1/sqrt(pi) * (P(0,x)*cc - Q(0,x)*ss) / sqrt(x)
253 * j0(x) = 1/sqrt(pi) * (P(0,x)*cc - Q(0,x)*ss) / sqrt(x)
278 return (u/v + tpi*(j0(x)*log(x)));
Indexes created Sat Sep 27 14:09:57 GMT 2025