public class FirstMoment extends AbstractStorelessUnivariateStatistic implements java.io.Serializable
mean = sum(x_i) / n
where n
is the number of observations.
To limit numeric errors, the value of the statistic is computed using the following recursive updating algorithm:
m =
the first valuem = m + (new value - m) / (number of observations)
Returns Double.NaN
if the dataset is empty.
Note that this implementation is not synchronized. If
multiple threads access an instance of this class concurrently, and at least
one of the threads invokes the increment()
or
clear()
method, it must be synchronized externally.
Constructor and Description |
---|
FirstMoment()
Create a FirstMoment instance
|
FirstMoment(FirstMoment original)
Copy constructor, creates a new
FirstMoment identical
to the original |
Modifier and Type | Method and Description |
---|---|
void |
clear()
Clears the internal state of the Statistic
|
FirstMoment |
copy()
Returns a copy of the statistic with the same internal state.
|
static void |
copy(FirstMoment source,
FirstMoment dest)
Copies source to dest.
|
long |
getN()
Returns the number of values that have been added.
|
double |
getResult()
Returns the current value of the Statistic.
|
void |
increment(double d)
Updates the internal state of the statistic to reflect the addition of the new value.
|
equals, evaluate, evaluate, hashCode, incrementAll, incrementAll
evaluate, getData, setData, setData
public FirstMoment()
public FirstMoment(FirstMoment original)
FirstMoment
identical
to the original
original
- the FirstMoment
instance to copypublic void increment(double d)
increment
in interface StorelessUnivariateStatistic
increment
in class AbstractStorelessUnivariateStatistic
d
- the new value.public void clear()
clear
in interface StorelessUnivariateStatistic
clear
in class AbstractStorelessUnivariateStatistic
public double getResult()
getResult
in interface StorelessUnivariateStatistic
getResult
in class AbstractStorelessUnivariateStatistic
Double.NaN
if it
has been cleared or just instantiated.public long getN()
getN
in interface StorelessUnivariateStatistic
public FirstMoment copy()
copy
in interface StorelessUnivariateStatistic
copy
in interface UnivariateStatistic
copy
in class AbstractStorelessUnivariateStatistic
public static void copy(FirstMoment source, FirstMoment dest)
Neither source nor dest can be null.
source
- FirstMoment to copydest
- FirstMoment to copy tojava.lang.NullPointerException
- if either source or dest is null"Copyright © 2010 - 2020 Adobe Systems Incorporated. All Rights Reserved"