RNG-179: Add fast loaded dice roller discrete sampler

apache · May 25, 2022 · 926da96 · 926da96
1 parent f97c0f8
commit 926da96
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Showing 5 changed files with 1,083 additions and 8 deletions.
diff --git a/...ons/rng/examples/jmh/sampling/distribution/EnumeratedDistributionSamplersPerformance.java b/...ons/rng/examples/jmh/sampling/distribution/EnumeratedDistributionSamplersPerformance.java
@@ -23,6 +23,7 @@
 import org.apache.commons.rng.UniformRandomProvider;
 import org.apache.commons.rng.sampling.distribution.AliasMethodDiscreteSampler;
 import org.apache.commons.rng.sampling.distribution.DiscreteSampler;
+import org.apache.commons.rng.sampling.distribution.FastLoadedDiceRollerSampler;
 import org.apache.commons.rng.sampling.distribution.GuideTableDiscreteSampler;
 import org.apache.commons.rng.sampling.distribution.MarsagliaTsangWangDiscreteSampler;
 import org.apache.commons.rng.simple.RandomSource;
@@ -41,7 +42,6 @@
 import org.openjdk.jmh.annotations.Warmup;
 
 import java.util.Arrays;
-import java.util.concurrent.ThreadLocalRandom;
 import java.util.concurrent.TimeUnit;
 import java.util.function.Supplier;
 
@@ -115,6 +115,7 @@ public abstract static class SamplerSources extends LocalRandomSources {
                 "AliasMethodDiscreteSampler",
                 "GuideTableDiscreteSampler",
                 "MarsagliaTsangWangDiscreteSampler",
+                "FastLoadedDiceRollerSampler",
 
                 // Uncomment to test non-default parameters
                 //"AliasMethodDiscreteSamplerNoPad", // Not optimal for sampling
@@ -187,6 +188,8 @@ private void createSamplerFactory(final UniformRandomProvider rng,
                 factory = () -> GuideTableDiscreteSampler.of(rng, probabilities, 8);
             } else if ("MarsagliaTsangWangDiscreteSampler".equals(samplerType)) {
                 factory = () -> MarsagliaTsangWangDiscreteSampler.Enumerated.of(rng, probabilities);
+            } else if ("FastLoadedDiceRollerSampler".equals(samplerType)) {
+                factory = () -> FastLoadedDiceRollerSampler.of(rng, probabilities);
             } else {
                 throw new IllegalStateException();
             }
@@ -335,12 +338,8 @@ public static class RandomDistributionSources extends SamplerSources {
         /** {@inheritDoc} */
         @Override
         protected double[] createProbabilities() {
-            final double[] probabilities = new double[randomNonUniformSize];
-            final ThreadLocalRandom rng = ThreadLocalRandom.current();
-            for (int i = 0; i < probabilities.length; i++) {
-                probabilities[i] = rng.nextDouble();
-            }
-            return probabilities;
+            return RandomSource.XO_RO_SHI_RO_128_PP.create()
+                .doubles(randomNonUniformSize).toArray();
         }
     }