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-rw-r--r-- | docs/mllib-statistics.md | 51 |
1 files changed, 47 insertions, 4 deletions
diff --git a/docs/mllib-statistics.md b/docs/mllib-statistics.md index 80a9d064c0..6acfc71d7b 100644 --- a/docs/mllib-statistics.md +++ b/docs/mllib-statistics.md @@ -438,22 +438,65 @@ run a 1-sample, 2-sided Kolmogorov-Smirnov test. The following example demonstra and interpret the hypothesis tests. {% highlight scala %} -import org.apache.spark.SparkContext -import org.apache.spark.mllib.stat.Statistics._ +import org.apache.spark.mllib.stat.Statistics val data: RDD[Double] = ... // an RDD of sample data // run a KS test for the sample versus a standard normal distribution val testResult = Statistics.kolmogorovSmirnovTest(data, "norm", 0, 1) println(testResult) // summary of the test including the p-value, test statistic, - // and null hypothesis - // if our p-value indicates significance, we can reject the null hypothesis + // and null hypothesis + // if our p-value indicates significance, we can reject the null hypothesis // perform a KS test using a cumulative distribution function of our making val myCDF: Double => Double = ... val testResult2 = Statistics.kolmogorovSmirnovTest(data, myCDF) {% endhighlight %} </div> + +<div data-lang="java" markdown="1"> +[`Statistics`](api/java/org/apache/spark/mllib/stat/Statistics.html) provides methods to +run a 1-sample, 2-sided Kolmogorov-Smirnov test. The following example demonstrates how to run +and interpret the hypothesis tests. + +{% highlight java %} +import java.util.Arrays; + +import org.apache.spark.api.java.JavaDoubleRDD; +import org.apache.spark.api.java.JavaSparkContext; + +import org.apache.spark.mllib.stat.Statistics; +import org.apache.spark.mllib.stat.test.KolmogorovSmirnovTestResult; + +JavaSparkContext jsc = ... +JavaDoubleRDD data = jsc.parallelizeDoubles(Arrays.asList(0.2, 1.0, ...)); +KolmogorovSmirnovTestResult testResult = Statistics.kolmogorovSmirnovTest(data, "norm", 0.0, 1.0); +// summary of the test including the p-value, test statistic, +// and null hypothesis +// if our p-value indicates significance, we can reject the null hypothesis +System.out.println(testResult); +{% endhighlight %} +</div> + +<div data-lang="python" markdown="1"> +[`Statistics`](api/python/pyspark.mllib.html#pyspark.mllib.stat.Statistics) provides methods to +run a 1-sample, 2-sided Kolmogorov-Smirnov test. The following example demonstrates how to run +and interpret the hypothesis tests. + +{% highlight python %} +from pyspark.mllib.stat import Statistics + +parallelData = sc.parallelize([1.0, 2.0, ... ]) + +# run a KS test for the sample versus a standard normal distribution +testResult = Statistics.kolmogorovSmirnovTest(parallelData, "norm", 0, 1) +print(testResult) # summary of the test including the p-value, test statistic, + # and null hypothesis + # if our p-value indicates significance, we can reject the null hypothesis +# Note that the Scala functionality of calling Statistics.kolmogorovSmirnovTest with +# a lambda to calculate the CDF is not made available in the Python API +{% endhighlight %} +</div> </div> |