diff --git a/src/site/xdoc/userguide/stat.xml b/src/site/xdoc/userguide/stat.xml
index bceaa20a9..e85a449c3 100644
--- a/src/site/xdoc/userguide/stat.xml
+++ b/src/site/xdoc/userguide/stat.xml
@@ -513,13 +513,13 @@ regression.addData(y, x, omega); // we do need covariance
where E(X)
is the mean of X
and E(Y)
is the mean of the Y
values. Non-bias-corrected estimates use
n
in place of n - 1.
Whether or not covariances are
- bias-corrected is determined by the optional constructor parameter,
- "biasCorrected," which defaults to true.
+ bias-corrected is determined by the optional parameter, "biasCorrected," which
+ defaults to true.
cor(X, Y) = sum[(xi - E(X))(yi - E(Y))] / [(n - 1)s(X)s(Y)]
+ PearsonsCorrelation computes correlations defined by the formula cor(X, Y) = sum[(xi - E(X))(yi - E(Y))] / [(n - 1)s(X)s(Y)]
E(X)
and E(Y)
are means of X
and Y
and s(X)
, s(Y)
are standard deviations.
data
using
+ associated with Pearson's correlation coefficients, start by creating a
+ PearsonsCorrelation
instance
@@ -593,16 +593,25 @@ correlation.getCorrelationStandardErrors();
SEr = ((1 - r2) / (n - 2))1/2
r
is the estimated correlation coefficient and
n
is the number of observations in the source dataset.RealMatrix
returned by
+ p-values for the (2-sided) null hypotheses that elements of
+ a correlation matrix are zero populate the RealMatrix returned by
- getCorrelationPValues().getEntry(i,j)
is the probability
- that a random variable distributed as tn-2
takes
+ getCorrelationPValues().getEntry(i,j)
is the
+ probability that a random variable distributed as tn-2
takes
a value with absolute value greater than or equal to |r|((n - 2) / (1 - r2))1/2
, where r
- is the estimated correlation coefficient.
+ |rij|((n - 2) / (1 - rij2))1/2
,
+ where rij
is the estimated correlation between the ith and jth
+ columns of the source array or RealMatrix. This is sometimes referred to as the
+ significance of the coefficient.data
is a RealMatrix with 2 columns and 10 rows, then
+
+ is the significance of the Pearson's correlation coefficient between the two columns
+ of data
. If this value is less than .01, we can say that the correlation
+ between the two columns of data is significant at the 99% level.
observed
values against
@@ -708,7 +717,7 @@ sampleStats = SummaryStatistics.newInstance();
for (int i = 0; i < observed.length; i++) {
sampleStats.addValue(observed[i]);
}
-System.out.println(TestUtils.t(mu, observed);
+System.out.println(TestUtils.t(mu, observed));