| java.lang.Object
 org.apache.commons.math.stat.StatUtils
| StatUtils | | final public class StatUtils (Code) | | StatUtils provides static methods for computing statistics based on data
stored in double[] arrays.
version:
$Revision: 233996 $ $Date: 2005-08-19 21:26:27 -0700 (Fri, 19 Aug 2005) $ |
| Method Summary | |
| public static double | geometricMean(double[] values)
Returns the geometric mean of the entries in the input array, or
Double.NaN if the array is empty. | | public static double | geometricMean(double[] values, int begin, int length)
Returns the geometric mean of the entries in the specified portion of
the input array, or Double.NaN if the designated subarray
is empty. | | public static double | max(double[] values)
Returns the maximum of the entries in the input array, or
Double.NaN if the array is empty.
Throws IllegalArgumentException if the array is null.
- The result is
NaN iff all values are NaN
(i.e. | | public static double | max(double[] values, int begin, int length)
Returns the maximum of the entries in the specified portion of
the input array, or Double.NaN if the designated subarray
is empty.
Throws IllegalArgumentException if the array is null or
the array index parameters are not valid.
- The result is
NaN iff all values are NaN
(i.e. | | public static double | mean(double[] values)
Returns the arithmetic mean of the entries in the input array, or
Double.NaN if the array is empty. | | public static double | mean(double[] values, int begin, int length)
Returns the arithmetic mean of the entries in the specified portion of
the input array, or Double.NaN if the designated subarray
is empty. | | public static double | meanDifference(double[] sample1, double[] sample2)
Returns the mean of the (signed) differences between corresponding elements of the
input arrays -- i.e., sum(sample1[i] - sample2[i]) / sample1.length. | | public static double | min(double[] values)
Returns the minimum of the entries in the input array, or
Double.NaN if the array is empty.
Throws IllegalArgumentException if the array is null.
- The result is
NaN iff all values are NaN
(i.e. | | public static double | min(double[] values, int begin, int length)
Returns the minimum of the entries in the specified portion of
the input array, or Double.NaN if the designated subarray
is empty.
Throws IllegalArgumentException if the array is null or
the array index parameters are not valid.
- The result is
NaN iff all values are NaN
(i.e. | | public static double | percentile(double[] values, double p)
Returns an estimate of the pth percentile of the values
in the values array. | | public static double | percentile(double[] values, int begin, int length, double p)
Returns an estimate of the pth percentile of the values
in the values array, starting with the element in (0-based)
position begin in the array and including length
values. | | public static double | product(double[] values)
Returns the product of the entries in the input array, or
Double.NaN if the array is empty. | | public static double | product(double[] values, int begin, int length)
Returns the product of the entries in the specified portion of
the input array, or Double.NaN if the designated subarray
is empty. | | public static double | sum(double[] values)
Returns the sum of the values in the input array, or
Double.NaN if the array is empty. | | public static double | sum(double[] values, int begin, int length)
Returns the sum of the entries in the specified portion of
the input array, or Double.NaN if the designated subarray
is empty. | | public static double | sumDifference(double[] sample1, double[] sample2)
Returns the sum of the (signed) differences between corresponding elements of the
input arrays -- i.e., sum(sample1[i] - sample2[i]). | | public static double | sumLog(double[] values)
Returns the sum of the natural logs of the entries in the input array, or
Double.NaN if the array is empty. | | public static double | sumLog(double[] values, int begin, int length)
Returns the sum of the natural logs of the entries in the specified portion of
the input array, or Double.NaN if the designated subarray
is empty. | | public static double | sumSq(double[] values)
Returns the sum of the squares of the entries in the input array, or
Double.NaN if the array is empty. | | public static double | sumSq(double[] values, int begin, int length)
Returns the sum of the squares of the entries in the specified portion of
the input array, or Double.NaN if the designated subarray
is empty. | | public static double | variance(double[] values)
Returns the variance of the entries in the input array, or
Double.NaN if the array is empty.
See
org.apache.commons.math.stat.descriptive.moment.Variance for
details on the computing algorithm.
Returns 0 for a single-value (i.e. | | public static double | variance(double[] values, int begin, int length)
Returns the variance of the entries in the specified portion of
the input array, or Double.NaN if the designated subarray
is empty.
See
org.apache.commons.math.stat.descriptive.moment.Variance for
details on the computing algorithm.
Returns 0 for a single-value (i.e. | | public static double | variance(double[] values, double mean, int begin, int length)
Returns the variance of the entries in the specified portion of
the input array, using the precomputed mean value. | | public static double | variance(double[] values, double mean)
Returns the variance of the entries in the input array, using the
precomputed mean value. | | public static double | varianceDifference(double[] sample1, double[] sample2, double meanDifference)
Returns the variance of the (signed) differences between corresponding elements of the
input arrays -- i.e., var(sample1[i] - sample2[i]). |
| geometricMean | | public static double geometricMean(double[] values)(Code) | | Returns the geometric mean of the entries in the input array, or
Double.NaN if the array is empty.
Throws IllegalArgumentException if the array is null.
See
org.apache.commons.math.stat.descriptive.moment.GeometricMean for details on the computing algorithm.
Parameters:
values - the input array the geometric mean of the values or Double.NaN if the array is empty
throws:
IllegalArgumentException - if the array is null |
| geometricMean | | public static double geometricMean(double[] values, int begin, int length)(Code) | | Returns the geometric mean of the entries in the specified portion of
the input array, or Double.NaN if the designated subarray
is empty.
Throws IllegalArgumentException if the array is null.
See
org.apache.commons.math.stat.descriptive.moment.GeometricMean for details on the computing algorithm.
Parameters:
values - the input array
Parameters:
begin - index of the first array element to include
Parameters:
length - the number of elements to include the geometric mean of the values or Double.NaN if length = 0
throws:
IllegalArgumentException - if the array is null or the array indexparameters are not valid |
| max | | public static double max(double[] values)(Code) | | Returns the maximum of the entries in the input array, or
Double.NaN if the array is empty.
Throws IllegalArgumentException if the array is null.
- The result is
NaN iff all values are NaN
(i.e. NaN values have no impact on the value of the statistic).
- If any of the values equals
Double.POSITIVE_INFINITY,
the result is Double.POSITIVE_INFINITY.
Parameters:
values - the input array the maximum of the values or Double.NaN if the array is empty
throws:
IllegalArgumentException - if the array is null |
| max | | public static double max(double[] values, int begin, int length)(Code) | | Returns the maximum of the entries in the specified portion of
the input array, or Double.NaN if the designated subarray
is empty.
Throws IllegalArgumentException if the array is null or
the array index parameters are not valid.
- The result is
NaN iff all values are NaN
(i.e. NaN values have no impact on the value of the statistic).
- If any of the values equals
Double.POSITIVE_INFINITY,
the result is Double.POSITIVE_INFINITY.
Parameters:
values - the input array
Parameters:
begin - index of the first array element to include
Parameters:
length - the number of elements to include the maximum of the values or Double.NaN if length = 0
throws:
IllegalArgumentException - if the array is null or the array indexparameters are not valid |
| mean | | public static double mean(double[] values)(Code) | | Returns the arithmetic mean of the entries in the input array, or
Double.NaN if the array is empty.
Throws IllegalArgumentException if the array is null.
See
org.apache.commons.math.stat.descriptive.moment.Mean for
details on the computing algorithm.
Parameters:
values - the input array the mean of the values or Double.NaN if the array is empty
throws:
IllegalArgumentException - if the array is null |
| mean | | public static double mean(double[] values, int begin, int length)(Code) | | Returns the arithmetic mean of the entries in the specified portion of
the input array, or Double.NaN if the designated subarray
is empty.
Throws IllegalArgumentException if the array is null.
See
org.apache.commons.math.stat.descriptive.moment.Mean for
details on the computing algorithm.
Parameters:
values - the input array
Parameters:
begin - index of the first array element to include
Parameters:
length - the number of elements to include the mean of the values or Double.NaN if length = 0
throws:
IllegalArgumentException - if the array is null or the array indexparameters are not valid |
| meanDifference | | public static double meanDifference(double[] sample1, double[] sample2) throws IllegalArgumentException(Code) | | Returns the mean of the (signed) differences between corresponding elements of the
input arrays -- i.e., sum(sample1[i] - sample2[i]) / sample1.length.
Parameters:
sample1 - the first array
Parameters:
sample2 - the second array mean of paired differences
throws:
IllegalArgumentException - if the arrays do not have the same(positive) length |
| min | | public static double min(double[] values)(Code) | | Returns the minimum of the entries in the input array, or
Double.NaN if the array is empty.
Throws IllegalArgumentException if the array is null.
- The result is
NaN iff all values are NaN
(i.e. NaN values have no impact on the value of the statistic).
- If any of the values equals
Double.NEGATIVE_INFINITY,
the result is Double.NEGATIVE_INFINITY.
Parameters:
values - the input array the minimum of the values or Double.NaN if the array is empty
throws:
IllegalArgumentException - if the array is null |
| min | | public static double min(double[] values, int begin, int length)(Code) | | Returns the minimum of the entries in the specified portion of
the input array, or Double.NaN if the designated subarray
is empty.
Throws IllegalArgumentException if the array is null or
the array index parameters are not valid.
- The result is
NaN iff all values are NaN
(i.e. NaN values have no impact on the value of the statistic).
- If any of the values equals
Double.NEGATIVE_INFINITY,
the result is Double.NEGATIVE_INFINITY.
Parameters:
values - the input array
Parameters:
begin - index of the first array element to include
Parameters:
length - the number of elements to include the minimum of the values or Double.NaN if length = 0
throws:
IllegalArgumentException - if the array is null or the array indexparameters are not valid |
| percentile | | public static double percentile(double[] values, double p)(Code) | | Returns an estimate of the pth percentile of the values
in the values array.
- Returns
Double.NaN if values has length
0
- Returns (for any value of
p) values[0]
if values has length 1
- Throws
IllegalArgumentException if values
is null or p is not a valid quantile value (p must be greater than 0
and less than or equal to 100)
See
org.apache.commons.math.stat.descriptive.rank.Percentile for
a description of the percentile estimation algorithm used.
Parameters:
values - input array of values
Parameters:
p - the percentile value to compute the percentile value or Double.NaN if the array is empty
throws:
IllegalArgumentException - if values is null or p is invalid |
| percentile | | public static double percentile(double[] values, int begin, int length, double p)(Code) | | Returns an estimate of the pth percentile of the values
in the values array, starting with the element in (0-based)
position begin in the array and including length
values.
- Returns
Double.NaN if length = 0
- Returns (for any value of
p) values[begin]
if length = 1
- Throws
IllegalArgumentException if values
is null , begin or length is invalid, or
p is not a valid quantile value (p must be greater than 0
and less than or equal to 100)
See
org.apache.commons.math.stat.descriptive.rank.Percentile for
a description of the percentile estimation algorithm used.
Parameters:
values - array of input values
Parameters:
p - the percentile to compute
Parameters:
begin - the first (0-based) element to include in the computation
Parameters:
length - the number of array elements to include the percentile value
throws:
IllegalArgumentException - if the parameters are not valid or theinput array is null |
| product | | public static double product(double[] values)(Code) | | Returns the product of the entries in the input array, or
Double.NaN if the array is empty.
Throws IllegalArgumentException if the array is null.
Parameters:
values - the input array the product of the values or Double.NaN if the array is empty
throws:
IllegalArgumentException - if the array is null |
| product | | public static double product(double[] values, int begin, int length)(Code) | | Returns the product of the entries in the specified portion of
the input array, or Double.NaN if the designated subarray
is empty.
Throws IllegalArgumentException if the array is null.
Parameters:
values - the input array
Parameters:
begin - index of the first array element to include
Parameters:
length - the number of elements to include the product of the values or Double.NaN if length = 0
throws:
IllegalArgumentException - if the array is null or the array indexparameters are not valid |
| sum | | public static double sum(double[] values)(Code) | | Returns the sum of the values in the input array, or
Double.NaN if the array is empty.
Throws IllegalArgumentException if the input array
is null.
Parameters:
values - array of values to sum the sum of the values or Double.NaN if the arrayis empty
throws:
IllegalArgumentException - if the array is null |
| sum | | public static double sum(double[] values, int begin, int length)(Code) | | Returns the sum of the entries in the specified portion of
the input array, or Double.NaN if the designated subarray
is empty.
Throws IllegalArgumentException if the array is null.
Parameters:
values - the input array
Parameters:
begin - index of the first array element to include
Parameters:
length - the number of elements to include the sum of the values or Double.NaN if length = 0
throws:
IllegalArgumentException - if the array is null or the array indexparameters are not valid |
| sumDifference | | public static double sumDifference(double[] sample1, double[] sample2) throws IllegalArgumentException(Code) | | Returns the sum of the (signed) differences between corresponding elements of the
input arrays -- i.e., sum(sample1[i] - sample2[i]).
Parameters:
sample1 - the first array
Parameters:
sample2 - the second array sum of paired differences
throws:
IllegalArgumentException - if the arrays do not have the same(positive) length |
| sumLog | | public static double sumLog(double[] values)(Code) | | Returns the sum of the natural logs of the entries in the input array, or
Double.NaN if the array is empty.
Throws IllegalArgumentException if the array is null.
See
org.apache.commons.math.stat.descriptive.summary.SumOfLogs .
Parameters:
values - the input array the sum of the natural logs of the values or Double.NaN if the array is empty
throws:
IllegalArgumentException - if the array is null |
| sumLog | | public static double sumLog(double[] values, int begin, int length)(Code) | | Returns the sum of the natural logs of the entries in the specified portion of
the input array, or Double.NaN if the designated subarray
is empty.
Throws IllegalArgumentException if the array is null.
See
org.apache.commons.math.stat.descriptive.summary.SumOfLogs .
Parameters:
values - the input array
Parameters:
begin - index of the first array element to include
Parameters:
length - the number of elements to include the sum of the natural logs of the values or Double.NaN if length = 0
throws:
IllegalArgumentException - if the array is null or the array indexparameters are not valid |
| sumSq | | public static double sumSq(double[] values)(Code) | | Returns the sum of the squares of the entries in the input array, or
Double.NaN if the array is empty.
Throws IllegalArgumentException if the array is null.
Parameters:
values - input array the sum of the squared values or Double.NaN if thearray is empty
throws:
IllegalArgumentException - if the array is null |
| sumSq | | public static double sumSq(double[] values, int begin, int length)(Code) | | Returns the sum of the squares of the entries in the specified portion of
the input array, or Double.NaN if the designated subarray
is empty.
Throws IllegalArgumentException if the array is null.
Parameters:
values - the input array
Parameters:
begin - index of the first array element to include
Parameters:
length - the number of elements to include the sum of the squares of the values or Double.NaN if length = 0
throws:
IllegalArgumentException - if the array is null or the array indexparameters are not valid |
| variance | | public static double variance(double[] values)(Code) | | Returns the variance of the entries in the input array, or
Double.NaN if the array is empty.
See
org.apache.commons.math.stat.descriptive.moment.Variance for
details on the computing algorithm.
Returns 0 for a single-value (i.e. length = 1) sample.
Throws IllegalArgumentException if the array is null.
Parameters:
values - the input array the variance of the values or Double.NaN if the array is empty
throws:
IllegalArgumentException - if the array is null |
| variance | | public static double variance(double[] values, int begin, int length)(Code) | | Returns the variance of the entries in the specified portion of
the input array, or Double.NaN if the designated subarray
is empty.
See
org.apache.commons.math.stat.descriptive.moment.Variance for
details on the computing algorithm.
Returns 0 for a single-value (i.e. length = 1) sample.
Throws IllegalArgumentException if the array is null or the
array index parameters are not valid.
Parameters:
values - the input array
Parameters:
begin - index of the first array element to include
Parameters:
length - the number of elements to include the variance of the values or Double.NaN if length = 0
throws:
IllegalArgumentException - if the array is null or the array indexparameters are not valid |
| variance | | public static double variance(double[] values, double mean, int begin, int length)(Code) | | Returns the variance of the entries in the specified portion of
the input array, using the precomputed mean value. Returns
Double.NaN if the designated subarray is empty.
See
org.apache.commons.math.stat.descriptive.moment.Variance for
details on the computing algorithm.
The formula used assumes that the supplied mean value is the arithmetic
mean of the sample data, not a known population parameter. This method
is supplied only to save computation when the mean has already been
computed.
Returns 0 for a single-value (i.e. length = 1) sample.
Throws IllegalArgumentException if the array is null or the
array index parameters are not valid.
Parameters:
values - the input array
Parameters:
mean - the precomputed mean value
Parameters:
begin - index of the first array element to include
Parameters:
length - the number of elements to include the variance of the values or Double.NaN if length = 0
throws:
IllegalArgumentException - if the array is null or the array indexparameters are not valid |
| variance | | public static double variance(double[] values, double mean)(Code) | | Returns the variance of the entries in the input array, using the
precomputed mean value. Returns Double.NaN if the array
is empty.
See
org.apache.commons.math.stat.descriptive.moment.Variance for
details on the computing algorithm.
The formula used assumes that the supplied mean value is the arithmetic
mean of the sample data, not a known population parameter. This method
is supplied only to save computation when the mean has already been
computed.
Returns 0 for a single-value (i.e. length = 1) sample.
Throws IllegalArgumentException if the array is null.
Parameters:
values - the input array
Parameters:
mean - the precomputed mean value the variance of the values or Double.NaN if the array is empty
throws:
IllegalArgumentException - if the array is null |
| varianceDifference | | public static double varianceDifference(double[] sample1, double[] sample2, double meanDifference) throws IllegalArgumentException(Code) | | Returns the variance of the (signed) differences between corresponding elements of the
input arrays -- i.e., var(sample1[i] - sample2[i]).
Parameters:
sample1 - the first array
Parameters:
sample2 - the second array
Parameters:
meanDifference - the mean difference between corresponding entries
See Also: StatUtils.meanDifference(double[],double[]) variance of paired differences
throws:
IllegalArgumentException - if the arrays do not have the samelength or their common length is less than 2. |
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