public static StableSampler of()

in commons-rng-sampling/src/main/java/org/apache/commons/rng/sampling/distribution/StableSampler.java [1356:1387]

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

    public static StableSampler of(UniformRandomProvider rng,
                                   double alpha,
                                   double beta,
                                   double gamma,
                                   double delta) {
        validateParameters(alpha, beta, gamma, delta);

        // Choose the algorithm.
        // Reuse the special cases as they have transformation support.

        if (alpha == ALPHA_GAUSSIAN) {
            // Note: beta has no effect and is ignored.
            return new GaussianStableSampler(rng, gamma, delta);
        }

        // Note: As beta -> 0 the result cannot be computed differently to beta = 0.
        if (alpha == ALPHA_CAUCHY && CMSStableSampler.getTau(ALPHA_CAUCHY, beta) == TAU_ZERO) {
            return new CauchyStableSampler(rng, gamma, delta);
        }

        if (alpha == ALPHA_LEVY && Math.abs(beta) == BETA_LEVY) {
            // Support mirroring for negative beta by inverting the beta=1 Levy sample
            // using a negative gamma. Note: The delta is not mirrored as it is a shift
            // applied to the scaled and mirrored distribution.
            return new LevyStableSampler(rng, beta * gamma, delta);
        }

        // Standardized sampler
        final StableSampler sampler = create(rng, alpha, beta);
        // Transform
        return new TransformedStableSampler(sampler, gamma, delta);
    }