/src/main/java/net/finmath/equities/models/Black76Model.java
impliedSdev = NormalDistribution.inverseCumulativeDistribution( sqrtThree * Math.pow( Math.abs( fRationalCubic / twoPi / x) , 1.0 / 0.6) ) ;
impliedSdev = NormalDistribution.inverseCumulativeDistribution ( sqrtThree * Math.pow ( Math.abs ( fRationalCubic / twoPi / x ) , 1.0 / 3.0 ) ) ;
final double fPrime = twoPi * zSquare * normDistOfZ * normDistOfZ * Math.exp(zSquare + sigmaLowerSquare / 8.0); final double fPrime2 = Math.PI * zSquare * normDistOfZ * Math.exp(2.0 * zSquare + sigmaLowerSquare / 4.0) / 6.0 / sigmaLowerSquare / sigmaLower + (3.0 * sigmaLowerSquare * (sigmaLowerSquare - 8.0) - 8.0 * x * x) * normDistOfZ / NormalDistribution.density(z)); final double r = (0.5 * fPrime2 * bLower + fPrime - 1.0) / (fPrime - fOfZ / bLower); final double fRationalCubic = rationalCubicInterpol(beta, 0.0, bLower, 0.0, fOfZ, 1.0, fPrime, r); <extra_id_0> impliedSdev = Math.abs(x / sqrtThree / impliedSdev); } else if (beta <= bCentral) { final double bPrimeLower1 = Math.exp(0.5 * (d1Lower * d1Lower + d2Lower * d2Lower)) * sqrtPi; final double bPrimeCentral1 = 1.0 / bPrimeCentral;