public class Variance extends Object implements Statistic
Var(X) = E[(X - E(X))2]This implementation uses Chan's update formula to incrementally compute the new statistic. The R equivalent function is
var
.Constructor and Description |
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Variance()
Construct an empty
Variance calculator. |
Variance(double[] data)
Construct an unbiased
Variance calculator. |
Variance(double[] data,
boolean unbiased)
Construct a
Variance calculator,
initialized with a sample. |
Variance(Variance that)
Copy constructor.
|
Modifier and Type | Method and Description |
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void |
addData(double... data)
Recompute the statistic with more data, incrementally if possible.
|
double |
mean()
Get the sample mean.
|
long |
N()
Get the size of the sample.
|
double |
standardDeviation()
Get the standard deviation of the sample,
which is the square root of the variance.
|
String |
toString() |
double |
value()
Get the value of the statistic.
|
public Variance()
Variance
calculator.public Variance(double[] data, boolean unbiased)
Variance
calculator,
initialized with a sample.data
- a sampleunbiased
- true
if the variance calculation uses the unbiased formulapublic Variance(double[] data)
Variance
calculator.data
- a samplepublic Variance(Variance that)
that
- a Variance
calculatorpublic double standardDeviation()
public void addData(double... data)
Statistic
public double value()
Statistic
public double mean()
public long N()
Statistic
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