static

in commons-rng-sampling/src/main/java/org/apache/commons/rng/sampling/distribution/ZigguratNormalizedGaussianSampler.java [58:95]

• 26 lines of code
• 2 McCabe index (conditional complexity)

    static {
        // Filling the tables.
        // Rectangle area.
        final double v = 0.00492867323399;
        // Direction support uses the sign bit so the maximum magnitude from the long is 2^63
        final double max = Math.pow(2, 63);
        final double oneOverMax = 1d / max;

        K = new long[LAST + 1];
        W = new double[LAST + 1];
        F = new double[LAST + 1];

        double d = R;
        double t = d;
        double fd = pdf(d);
        final double q = v / fd;

        K[0] = (long) ((d / q) * max);
        K[1] = 0;

        W[0] = q * oneOverMax;
        W[LAST] = d * oneOverMax;

        F[0] = 1;
        F[LAST] = fd;

        for (int i = LAST - 1; i >= 1; i--) {
            d = Math.sqrt(-2 * Math.log(v / d + fd));
            fd = pdf(d);

            K[i + 1] = (long) ((d / t) * max);
            t = d;

            F[i] = fd;

            W[i] = d * oneOverMax;
        }
    }