psteitz 2004/03/21 12:32:50
Modified: math/xdocs/userguide stat.xml
Log:
Formatting.
Revision Changes Path
1.13 +25 -18 jakarta-commons/math/xdocs/userguide/stat.xml
Index: stat.xml
===================================================================
RCS file: /home/cvs/jakarta-commons/math/xdocs/userguide/stat.xml,v
retrieving revision 1.12
retrieving revision 1.13
diff -u -r1.12 -r1.13
--- stat.xml 7 Mar 2004 00:56:14 -0000 1.12
+++ stat.xml 21 Mar 2004 20:32:50 -0000 1.13
@@ -57,7 +57,7 @@
all statistics, consists of <code>evaluate()</code> methods that take
double[] arrays as arguments and return
the value of the statistic. This interface is extended by
<a
href="../apidocs/org/apache/commons/math/stat/univariate/StorelessUnivariateStatistic.html">
- StorelessUnivariateStatistic,</a> which adds <code>increment(),</code>
+ StorelessUnivariateStatistic</a>, which adds <code>increment(),</code>
<code>getResult()</code> and associated methods to support "storageless"
implementations that
maintain counters, sums or other state information as values are added
using the <code>increment()</code>
method.
@@ -76,10 +76,16 @@
There are several ways to instantiate and use statistics. Statistics can
be instantiated and used directly, but it is
generally more convenient (and efficient) to access them using the
provided aggregates, <a
href="../apidocs/org/apache/commons/math/stat/DescriptiveStatistics.html">
DescriptiveStatistics</a> and <a
href="../apidocs/org/apache/commons/math/stat/SummaryStatistics.html">
- SummaryStatistics.</a> <code>DescriptiveStatistics</code> maintains
the input data in memory and has the capability
- of producing "rolling" statistics computed from a "window" consisting
of the most recently added values. <code>SummaryStatisics</code>
- does not store the input data values in memory, so the statistics
included in this aggregate are limited to those that can be
- computed in one pass through the data without access to the full array
of values.
+ SummaryStatistics.</a>
+ </p>
+ <p>
+ <code>DescriptiveStatistics</code> maintains the input data in memory
and has the capability
+ of producing "rolling" statistics computed from a "window" consisting
of the most recently added values.
+ </p>
+ <p>
+ <code>SummaryStatisics</code> does not store the input data values in
memory, so the statistics
+ included in this aggregate are limited to those that can be computed in
one pass through the data
+ without access to the full array of values.
</p>
<p>
<table>
@@ -92,8 +98,7 @@
</p>
<p>
There is also a utility class, <a
href="../apidocs/org/apache/commons/math/stat/StatUtils.html">
- StatUtils,</a> that provides static methods for computing statistics
- directly from double[] arrays.
+ StatUtils</a>, that provides static methods for computing statistics
directly from double[] arrays.
</p>
<p>
Here are some examples showing how to compute univariate statistics.
@@ -140,6 +145,7 @@
double mean = StatUtils.mean(values);
double std = StatUtils.variance(values);
double median = StatUtils.percentile(50);
+
// Compute the mean of the first three values in the array
mean = StatuUtils.mean(values, 0, 3);
</source>
@@ -151,6 +157,7 @@
// Create a DescriptiveStats instance and set the window size to 100
DescriptiveStatistics stats = DescriptiveStatistics.newInstance();
stats.setWindowSize(100);
+
// Read data from an input stream, displaying the mean of the most recent 100
observations
// after every 100 observations
long nLines = 0;
@@ -177,7 +184,7 @@
values.
</p>
<p>
- Strings, integers, longs, chars are all supported as value types, as well
as instances
+ Strings, integers, longs and chars are all supported as value types, as
well as instances
of any class that implements <code>Comparable.</code> The ordering of
values
used in computing cumulative frequencies is by default the <i>natural
ordering,</i>
but this can be overriden by supplying a <code>Comparator</code> to the
constructor.
@@ -197,11 +204,11 @@
f.addValue(new Long(1));
f.addValue(2)
f.addValue(new Integer(-1));
- System.out.prinltn(f.getCount(1)); // displays 3
- System.out.println(f.getCumPct(0)); // displays 0.2
- System.out.println(f.getPct(new Integer(1))); // displays 0.6
- System.out.println(f.getCumPct(-2)); // displays 0 -- all values are greater
than this
- System.out.println(f.getCumPct(10)); // displays 1 -- all values are less than
this
+ System.out.prinltn(f.getCount(1)); // displays 3
+ System.out.println(f.getCumPct(0)); // displays 0.2
+ System.out.println(f.getPct(new Integer(1))); // displays 0.6
+ System.out.println(f.getCumPct(-2)); // displays 0 -- all values are
greater than this
+ System.out.println(f.getCumPct(10)); // displays 1 -- all values are
less than this
</source>
</dd>
<dt>Count string frequencies</dt>
@@ -213,9 +220,9 @@
f.addValue("One");
f.addValue("oNe");
f.addValue("Z");
-System.out.println(f.getCount("one")); // displays 1
-System.out.println(f.getCumPct("Z")); // displays 0.5 -- second in sort order
-System.out.println(f.getCumPct("Ot")); // displays 0.25 -- between first ("One")
and second ("Z") value
+System.out.println(f.getCount("one")); // displays 1
+System.out.println(f.getCumPct("Z")); // displays 0.5 -- second in sort order
+System.out.println(f.getCumPct("Ot")); // displays 0.25 -- between first ("One")
and second ("Z") value
</source>
</dd>
<dd>Using case-insensitive comparator:
@@ -226,7 +233,7 @@
f.addValue("oNe");
f.addValue("Z");
System.out.println(f.getCount("one")); // displays 3
-System.out.println(f.getCumPct("z")); // displays 1 -- last value
+System.out.println(f.getCumPct("z")); // displays 1 -- last value
</source>
</dd>
</dl>
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