SampleRecorder

java.lang.Object
- com.freevariable.lancer.util.SampleRecorder

```
public final class SampleRecorder
extends java.lang.Object
```
A class to manage aggregate statistics for a stream of double values in constant space. Uses the technique from "Updating mean and variance estimates: an improved method", by D. H. D. West (1979).

Since:

0.0.1

Field Summary

Fields
Modifier and Type	Field	Description
`private long`	`count`
`private double`	`max`
`private double`	`meanEstimate`
`private double`	`min`
`private boolean`	`sd_dirty`
`private double`	`stdDevEstimate`
`private double`	`sumX`
`private double`	`sumXSquared`
`private double`	`varianceEstimate`

Constructor Summary

Constructors
Constructor Description

SampleRecorder()

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`long`	`count()`	Returns the count of samples recorded so far.
`double`	`max()`	Returns the largest sample recorded so far.
`double`	`meanEstimate()`	Returns the estimated mean of samples recorded so far.
`double`	`min()`	Returns the smallest sample recorded so far.
`void`	`record(double sample)`	Records the given sample.
`void`	`reset()`
`double`	`stdDevEstimate()`	Returns the estimated standard deviation of samples recorded so far; this is computed by need.
`private void`	`updateEstimates(double sample)`
`double`	`varianceEstimate()`	Returns the estimated variance of samples recorded so far.

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

- Field Detail
  - count
```
private long count
```
  - meanEstimate
```
private double meanEstimate
```
  - varianceEstimate
```
private double varianceEstimate
```
  - stdDevEstimate
```
private double stdDevEstimate
```
  - sd_dirty
```
private boolean sd_dirty
```
  - max
```
private double max
```
  - min
```
private double min
```
  - sumX
```
private double sumX
```
  - sumXSquared
```
private double sumXSquared
```
- Constructor Detail
  - SampleRecorder
```
public SampleRecorder()
```
- Method Detail
  - updateEstimates
```
private void updateEstimates(double sample)
```
  - reset
```
public void reset()
```
  - record
```
public void record(double sample)
```
    Records the given sample.
  - count
```
public long count()
```
    Returns the count of samples recorded so far.
  - meanEstimate
```
public double meanEstimate()
```
    Returns the estimated mean of samples recorded so far.
  - varianceEstimate
```
public double varianceEstimate()
```
    Returns the estimated variance of samples recorded so far.
  - stdDevEstimate
```
public double stdDevEstimate()
```
    Returns the estimated standard deviation of samples recorded so far; this is computed by need.
  - max
```
public double max()
```
    Returns the largest sample recorded so far.
  - min
```
public double min()
```
    Returns the smallest sample recorded so far.