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author | Aleksandar Prokopec <axel22@gmail.com> | 2012-06-06 20:16:39 +0200 |
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committer | Aleksandar Prokopec <axel22@gmail.com> | 2012-06-06 20:16:39 +0200 |
commit | daca24d8e7050eab9551b123cef010d7bf33f803 (patch) | |
tree | ba69ecd42e915de29a31ba9df50c2fb52bab69b5 /test/files | |
parent | db1b777372a6883f9c474159804b8f7798c0ec49 (diff) | |
download | scala-daca24d8e7050eab9551b123cef010d7bf33f803.tar.gz scala-daca24d8e7050eab9551b123cef010d7bf33f803.tar.bz2 scala-daca24d8e7050eab9551b123cef010d7bf33f803.zip |
Fix SI-5880.
Add a ChiSquare test for the new hash code.
Diffstat (limited to 'test/files')
-rw-r--r-- | test/files/run/t5880.scala | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/test/files/run/t5880.scala b/test/files/run/t5880.scala new file mode 100644 index 0000000000..08cd0d6bf8 --- /dev/null +++ b/test/files/run/t5880.scala @@ -0,0 +1,41 @@ + + +import scala.collection.JavaConversions._ + + + +object Test { + + def main(args:Array[String]) = { + val tests = 5000 + val jm: java.util.Map[Int, Int] = scala.collection.mutable.Map((0 until tests) zip (0 until tests).reverse: _*) + val es = jm.entrySet() + val it = es.iterator + + // chi square test + val groups = 10 + val hits = new Array[Int](groups) + def hit(hc: Int) { + val bucket = math.abs(hc) / (Int.MaxValue / groups) + hits(bucket) += 1 + } + def expected = tests / groups + def Dstat = { + val diffs = for (i <- 0 until groups) yield math.abs(hits(i) - expected) + diffs.sum.toDouble / expected + } + def ChiSquare = { + val diffs = for (i <- 0 until groups) yield (hits(i) - expected) * (hits(i) - expected) + diffs.sum.toDouble / expected + } + + while (it.hasNext) { + val x = it.next() + hit(x.##) + } + // println(hits.toBuffer) + // println(ChiSquare) + assert(ChiSquare < 2.0) + } + +} |