Lines Matching defs:erf
16 /* double erf(double x)
20 * erf(x) = --------- | exp(-t*t)dt
24 * erfc(x) = 1-erf(x)
26 * erf(-x) = -erf(x)
31 * erf(x) = x + x*R(x^2)
32 * erfc(x) = 1 - erf(x) if x in [-.84375,0.25]
37 * | R - (erf(x)-x)/x | <= 2
41 * erf(x) = (2/sqrt(pi))*(x - x^3/3 + x^5/10 - x^7/42 + ....)
45 * point of erf(x) is near 0.6174 (i.e., erf(x)=x when x is
47 * guarantee the error is less than one ulp for erf.
51 * erf(x) = sign(x) * (c + P1(s)/Q1(s))
54 * |P1/Q1 - (erf(|x|)-c)| <= 2**-59.06
56 * erf(1+s) = erf(1) + s*Poly(s)
59 * erf(1+s) - (c = (single)0.84506291151)
67 * erf(x) = 1 - erfc(x)
76 * erf(x) = sign(x)*(1.0 - erfc(x)) if x < 6, else
77 * erf(x) = sign(x)*(1.0 - tiny)
100 * erf(x) = sign(x) *(1 - tiny) (raise inexact)
105 * erf(0) = 0, erf(inf) = 1, erf(-inf) = -1,
107 * erfc/erf(NaN) is NaN
122 * Coefficients for approximation to erf on [0,0.84375]
137 * Coefficients for approximation to erf in [0.84375,1.25]
190 erf(double x)
196 if(ix>=0x7ff00000) { /* erf(nan)=nan */
198 return (double)(1-i)+one/x; /* erf(+-inf)=+-1 */
