org.statcato.statistics.inferential.nonparametrics
Class WilcoxonSignedRankTest

java.lang.Object
  extended by org.statcato.statistics.inferential.nonparametrics.WilcoxonSignedRankTest

public class WilcoxonSignedRankTest
extends java.lang.Object

Wilcoxon Signed Rank test. A nonparametic test for claims regarding the median of a single population. Samples are ranked by their absolute distances from the hypothesized median. The ranks of sample values that are above the hypothesized median are given positive signs; those of values below the hypothesized median are given negative signs. The sums of the ranks corresponding to positive and negative signs are computed, respectively. The rank sums are used as test statistics.

Since:
1.0
Version:
%I%, %G%
Author:
Margaret Yau

Field Summary
static int GREATER
          Alternative hypothesis type: greater than
static int LESS
          Alternative hypothesis type: less than
static int NOTEQUAL
          Alternative hypothesis type: not equal to
 double significance
          Significance of the test.
 
Constructor Summary
WilcoxonSignedRankTest(java.util.Vector<java.lang.Double> data, double testMedian, int testType, double significance)
          Constructor, given data values.
 
Method Summary
 double getRankSum(java.util.Vector<java.lang.Double> data)
          Returns the rank sum of the given data (negative rank sum for right-tailed test, positive rank sum for left-tailed, and minimum of the two rank sums for two-tailed).
 double pValue()
          Returns the p-value.
 java.lang.String toString()
           
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Field Detail

LESS

public static int LESS
Alternative hypothesis type: less than


GREATER

public static int GREATER
Alternative hypothesis type: greater than


NOTEQUAL

public static int NOTEQUAL
Alternative hypothesis type: not equal to


significance

public double significance
Significance of the test.

Constructor Detail

WilcoxonSignedRankTest

public WilcoxonSignedRankTest(java.util.Vector<java.lang.Double> data,
                              double testMedian,
                              int testType,
                              double significance)
Constructor, given data values.

Parameters:
data - vector of double values
testMedian - hypothesized median
testType - type of alternative hypothesis
Method Detail

pValue

public double pValue()
Returns the p-value.

Returns:
p-value

toString

public java.lang.String toString()
Overrides:
toString in class java.lang.Object

getRankSum

public double getRankSum(java.util.Vector<java.lang.Double> data)
Returns the rank sum of the given data (negative rank sum for right-tailed test, positive rank sum for left-tailed, and minimum of the two rank sums for two-tailed).

Parameters:
data - vector of Double values
Returns:
rank sum