private double fix()

in commons-rng-sampling/src/main/java/org/apache/commons/rng/sampling/distribution/ZigguratNormalizedGaussianSampler.java [131:164]

• 18 lines of code
• 5 McCabe index (conditional complexity)

    private double fix(long hz,
                       int iz) {
        if (iz == 0) {
            // Base strip.
            // This branch is called about 2.55224E-4 times per sample.
            double y;
            double x;
            do {
                // Avoid infinity by creating a non-zero double.
                // Note: The extreme value y from -Math.log(2^-53) is (to 4 sf):
                // y = 36.74
                // The largest value x where 2y < x^2 is false is sqrt(2*36.74):
                // x = 8.571
                // The extreme tail is:
                // out = +/- 12.01
                // To generate this requires longs of 0 and then (1377 << 11).
                y = -Math.log(InternalUtils.makeNonZeroDouble(rng.nextLong()));
                x = -Math.log(InternalUtils.makeNonZeroDouble(rng.nextLong())) * ONE_OVER_R;
            } while (y + y < x * x);

            final double out = R + x;
            return hz > 0 ? out : -out;
        }
        // Wedge of other strips.
        // This branch is called about 0.0146584 times per sample.
        final double x = hz * W[iz];
        if (F[iz] + rng.nextDouble() * (F[iz - 1] - F[iz]) < pdf(x)) {
            // This branch is called about 0.00797887 times per sample.
            return x;
        }
        // Try again.
        // This branch is called about 0.00667957 times per sample.
        return sample();
    }