Statistics (S-Space Package 2.0.1 API)

java.lang.Object
- edu.ucla.sspace.common.Statistics

```
public class Statistics
extends Object
```
A collection of static methods for statistical analysis and basic numeric computation.

Method Summary

Methods
Modifier and Type	Method and Description
`static double`	`entropy(double[] a)` Returns the entropy of the array.
`static double`	`entropy(int[] a)` Returns the entropy of the array.
`static double`	`log2_1p(double d)` Returns the base-2 logarithm of `d + 1`.
`static double`	`log2(double d)` Returns the base-2 logarithm of `d`.
`static double`	`mean(Collection<? extends Number> values)` Returns the mean value of the collection of numbers
`static double`	`mean(double[] values)` Returns the mean value of the array of doubles
`static double`	`mean(int[] values)` Returns the mean value of the array of ints
`static <T extends Number & Comparable> T`	`median(Collection<T> values)` Returns the median value of the collection of numbers
`static double`	`median(double[] values)` Returns the median value of the array of doubles
`static double`	`median(int[] values)` Returns the median value of the array of ints
`static BitSet`	`randomDistribution(int valuesToSet, int range)` Randomly sets `valuesToSet` values to `true` for a sequence from [0:`range`).
`static double`	`stddev(Collection<? extends Number> values)` Returns the standard deviation of the collection of numbers
`static double`	`stddev(double[] values)` Returns the standard deviation of the values in the double array
`static double`	`stddev(int[] values)` Returns the standard deviation of the values in the int array
`static double`	`sum(Collection<? extends Number> values)` Returns the sum of the collection of numbers
`static double`	`sum(double[] values)` Returns the sum of the values in the double array
`static int`	`sum(int[] values)` Returns the sum of the values in the int array

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Method Detail
  - entropy
```
public static double entropy(int[] a)
```
    Returns the entropy of the array.
  - entropy
```
public static double entropy(double[] a)
```
    Returns the entropy of the array.
  - log2
```
public static double log2(double d)
```
    Returns the base-2 logarithm of d.
  - log2_1p
```
public static double log2_1p(double d)
```
    Returns the base-2 logarithm of d + 1.
    
    See Also:
    Math.log1p(double)
  - mean
```
public static double mean(Collection<? extends Number> values)
```
    Returns the mean value of the collection of numbers
  - mean
```
public static double mean(int[] values)
```
    Returns the mean value of the array of ints
  - mean
```
public static double mean(double[] values)
```
    Returns the mean value of the array of doubles
  - median
```
public static <T extends Number & Comparable> T median(Collection<T> values)
```
    Returns the median value of the collection of numbers
  - median
```
public static double median(int[] values)
```
    Returns the median value of the array of ints
  - median
```
public static double median(double[] values)
```
    Returns the median value of the array of doubles
  - randomDistribution
```
public static BitSet randomDistribution(int valuesToSet,
                        int range)
```
    Randomly sets valuesToSet values to true for a sequence from [0:range).
    
    Parameters:
    valuesToSet - the number of values that are to be set to true in the distribution
    range - the total number of values in the sequence.
  - stddev
```
public static double stddev(Collection<? extends Number> values)
```
    Returns the standard deviation of the collection of numbers
  - stddev
```
public static double stddev(int[] values)
```
    Returns the standard deviation of the values in the int array
  - stddev
```
public static double stddev(double[] values)
```
    Returns the standard deviation of the values in the double array
  - sum
```
public static double sum(Collection<? extends Number> values)
```
    Returns the sum of the collection of numbers
  - sum
```
public static int sum(int[] values)
```
    Returns the sum of the values in the int array
  - sum
```
public static double sum(double[] values)
```
    Returns the sum of the values in the double array

Class Statistics

Method Summary

Methods inherited from class java.lang.Object

Method Detail

entropy

entropy

log2

log2_1p

mean

mean

mean

median

median

median

randomDistribution

stddev

stddev

stddev

sum

sum

sum