ColumnStats

java.lang.Object
- kcl.waterloo.math.ColumnStats

```
public class ColumnStats
extends java.lang.Object
```
Provides basic statistics for the columns of a double[][] array. Columns should contain the same number of elements. Missing values should be entered as NaNs. Statistics available are :
Sum

Mean

Variance

Standard deviation

Skew

Kurtosis

Minimum

Maximum

Median

Upper and Lower percentiles

Number of valid (non-NaN) values
Geometric mean

NaNs are treated as missing values and discounted from all calculations.
An internal matrix contains the following parameters in the rows specified by ColumnStats.X where X is a static final int.
ColumnStats.SUM the sum of values.

ColumnStats.SUMDELTA2 the sum of squares of residuals.

ColumnStats.SUMDELTA3 the sum of cubes of residuals.
ColumnStats.SUMDELTA4 the sum of residuals to power 4.
ColumnStats.MIN minimum value.

ColumnStats.MAX maximum value.

ColumnStats.MEDIAN median value.

ColumnStats.LOWER lower percent.

ColumnStats.UPPER upper percent.

ColumnStats.SUMLOG sum of logs.

ColumnStats.N number of observations (discounting NaNs).

ColumnStats.Pct the requested percent (0 to 50):

LOWER contains these values while UPPER contains values for percent = (100-ColumnStats.Pct).

Field Summary

Fields
Modifier and Type	Field and Description
`static int`	`LOWER`
`static int`	`MAX`
`static int`	`MEDIAN`
`static int`	`MIN`
`static int`	`N`
`static int`	`SUM`
`static int`	`SUMDELTA2`
`static int`	`SUMDELTA3`
`static int`	`SUMDELTA4`
`static int`	`SUMLOG`
`static int`	`UPPER`

Constructor Summary

Constructors
Constructor and Description
`ColumnStats(double[][] data)` Returns statistics using 25th/75th percentiles
`ColumnStats(double[][] data, int percentile)` Returns statistics using specified percentiles

Method Summary

Methods
Modifier and Type	Method and Description
`int`	`getDimension()` Returns the number of columns for the input array.
`double[][]`	`getGeometricMean()` Returns the geometric mean for each column of the data.
`double[][]`	`getKurtosis()` Returns the kurtosis of the data in each column of the input.
`double[][]`	`getLower()` Returns the lower pecentile for each column of the data.
`double[][]`	`getMaximum()` Returns the maximum value for each column of the data.
`double[][]`	`getMean()` Returns the mean of the data in each column of the input.
`double[][]`	`getMedian()` Returns the median value for each column of the data.
`double[][]`	`getMinimum()` Returns the minimum value for each column of the data.
`double[][]`	`getN()` Returns the number of data points for each column of the data.
`double`	`getPercentile()` Returns the lower pecentile used.
`double[][]`	`getSD()` Returns the standard deviation of the data in each column of the input.
`double[][]`	`getSkew()` Returns the skew of the data in each column of the input.
`double[][]`	`getSum()` Returns the sum of the data in each column of the input.
`double[][]`	`getSummary()` Returns a copy of the intermediate array used in calculations.
`double[][]`	`getUpper()` Returns the upper pecentile for each column of the data.
`double[][]`	`getVariance()` Returns the variance of the data in each column of the input.
`boolean`	`isKurtosisCorrected()` Returns true if bias correction is to be applied to the kurtosis
`boolean`	`isSkewCorrected()` Returns true if bias correction is to be applied to the skew
`boolean`	`isVarianceCorrected()` Returns true if bias correction is to be applied to the variance
`void`	`setKurtosisCorrected(boolean flag)` Sets bias correction mode for the kurtosis
`void`	`setSkewCorrected(boolean flag)` Sets bias correction mode for the skew
`void`	`setVarianceCorrected(boolean flag)` Sets bias correction mode for the variance (and standard deviation)
`java.lang.String`	`toString()`

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

- Field Detail
  - SUM
```
public static final int SUM
```
    See Also:
    Constant Field Values
  - SUMDELTA2
```
public static final int SUMDELTA2
```
    See Also:
    Constant Field Values
  - SUMDELTA3
```
public static final int SUMDELTA3
```
    See Also:
    Constant Field Values
  - SUMDELTA4
```
public static final int SUMDELTA4
```
    See Also:
    Constant Field Values
  - MIN
```
public static final int MIN
```
    See Also:
    Constant Field Values
  - MAX
```
public static final int MAX
```
    See Also:
    Constant Field Values
  - MEDIAN
```
public static final int MEDIAN
```
    See Also:
    Constant Field Values
  - LOWER
```
public static final int LOWER
```
    See Also:
    Constant Field Values
  - UPPER
```
public static final int UPPER
```
    See Also:
    Constant Field Values
  - SUMLOG
```
public static final int SUMLOG
```
    See Also:
    Constant Field Values
  - N
```
public static final int N
```
    See Also:
    Constant Field Values
- Constructor Detail
  - ColumnStats
```
public ColumnStats(double[][] data)
```
    Returns statistics using 25th/75th percentiles
    
    Parameters:
    data - the data to analyze
  - ColumnStats
```
public ColumnStats(double[][] data,
           int percentile)
```
    Returns statistics using specified percentiles
    
    Parameters:
    data - the data to analyze
    percentile - the percentiles to use
- Method Detail
  - getDimension
```
public int getDimension()
```
    Returns the number of columns for the input array.
    
    Returns:
    number of columns
  - getSum
```
public double[][] getSum()
```
    Returns the sum of the data in each column of the input.
    
    Returns:
    the sum
  - getMean
```
public double[][] getMean()
```
    Returns the mean of the data in each column of the input.
    
    Returns:
    the mean
  - getVariance
```
public double[][] getVariance()
```
    Returns the variance of the data in each column of the input. Bias correction is applied if varianeCorrected is true.
    
    Returns:
    the variance
  - getSD
```
public double[][] getSD()
```
    Returns the standard deviation of the data in each column of the input. Bias correction is applied to the variance if varianceCorrected is true.
    
    Returns:
    the standard deviation
  - getSkew
```
public double[][] getSkew()
```
    Returns the skew of the data in each column of the input. Bias correction is applied to the variance if skewCorrected is true.
    
    Returns:
    the skew
  - getKurtosis
```
public double[][] getKurtosis()
```
    Returns the kurtosis of the data in each column of the input. Bias correction is applied to the variance if kurtosisCorrected is true.
    
    Returns:
    the kurtosis
  - getMinimum
```
public double[][] getMinimum()
```
    Returns the minimum value for each column of the data.
    
    Returns:
    the minimum
  - getMaximum
```
public double[][] getMaximum()
```
    Returns the maximum value for each column of the data.
    
    Returns:
    the maximum
  - getGeometricMean
```
public double[][] getGeometricMean()
```
    Returns the geometric mean for each column of the data.
    
    Returns:
    the geometric mean
  - getN
```
public double[][] getN()
```
    Returns the number of data points for each column of the data. NaNs are excluded.
    
    Returns:
    the number of data points
  - getMedian
```
public double[][] getMedian()
```
    Returns the median value for each column of the data.
    
    Returns:
    the median
  - getLower
```
public double[][] getLower()
```
    Returns the lower pecentile for each column of the data.
    
    Returns:
    the lower pecentile
  - getUpper
```
public double[][] getUpper()
```
    Returns the upper pecentile for each column of the data.
    
    Returns:
    the upper pecentile
  - getPercentile
```
public double getPercentile()
```
    Returns the lower pecentile used. The upper percentile is (100-lower percentile)
    
    Returns:
    the pecentile
  - getSummary
```
public double[][] getSummary()
```
    Returns a copy of the intermediate array used in calculations.
    
    Returns:
    a double[][]
  - isVarianceCorrected
```
public boolean isVarianceCorrected()
```
    Returns true if bias correction is to be applied to the variance
    
    Returns:
    the correction flag
  - setVarianceCorrected
```
public void setVarianceCorrected(boolean flag)
```
    Sets bias correction mode for the variance (and standard deviation)
    
    Parameters:
    flag -
  - isSkewCorrected
```
public boolean isSkewCorrected()
```
    Returns true if bias correction is to be applied to the skew
    
    Returns:
    the correction flag
  - setSkewCorrected
```
public void setSkewCorrected(boolean flag)
```
    Sets bias correction mode for the skew
    
    Parameters:
    flag -
  - isKurtosisCorrected
```
public boolean isKurtosisCorrected()
```
    Returns true if bias correction is to be applied to the kurtosis
    
    Returns:
    the correction flag
  - setKurtosisCorrected
```
public void setKurtosisCorrected(boolean flag)
```
    Sets bias correction mode for the kurtosis
    
    Parameters:
    flag -
  - toString
```
public java.lang.String toString()
```
    Overrides:
    
    toString in class java.lang.Object

Class ColumnStats

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

SUM

SUMDELTA2

SUMDELTA3

SUMDELTA4

MIN

MAX

MEDIAN

LOWER

UPPER

SUMLOG

N

Constructor Detail

ColumnStats

ColumnStats

Method Detail

getDimension

getSum

getMean

getVariance

getSD

getSkew

getKurtosis

getMinimum

getMaximum

getGeometricMean

getN

getMedian

getLower

getUpper

getPercentile

getSummary

isVarianceCorrected

setVarianceCorrected

isSkewCorrected

setSkewCorrected

isKurtosisCorrected

setKurtosisCorrected

toString