ValueServer (Apache Commons Math 3.6.1 API)

java.lang.Object
- org.apache.commons.math3.random.ValueServer

```
public class ValueServer
extends Object
```
Generates values for use in simulation applications.
How values are generated is determined by the mode property.

Supported mode values are:
- DIGEST_MODE -- uses an empirical distribution
- REPLAY_MODE -- replays data from valuesFileURL
- UNIFORM_MODE -- generates uniformly distributed random values with mean = mu
- EXPONENTIAL_MODE -- generates exponentially distributed random values with mean = mu
- GAUSSIAN_MODE -- generates Gaussian distributed random values with mean = mu and standard deviation = sigma
- CONSTANT_MODE -- returns mu every time.

Field Summary

Fields
Modifier and Type	Field and Description
`static int`	`CONSTANT_MODE` Always return mu
`static int`	`DIGEST_MODE` Use empirical distribution.
`static int`	`EXPONENTIAL_MODE` Exponential random deviates with mean = μ.
`static int`	`GAUSSIAN_MODE` Gaussian random deviates with mean = μ, std dev = σ.
`static int`	`REPLAY_MODE` Replay data from valuesFilePath.
`static int`	`UNIFORM_MODE` Uniform random deviates with mean = μ.

Constructor Summary

Constructors
Constructor and Description
`ValueServer()` Creates new ValueServer
`ValueServer(RandomDataImpl randomData)` Deprecated. use `ValueServer(RandomGenerator)`
`ValueServer(RandomGenerator generator)` Construct a ValueServer instance using a RandomGenerator as its source of random data.

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`closeReplayFile()` Closes `valuesFileURL` after use in REPLAY_MODE.
`void`	`computeDistribution()` Computes the empirical distribution using values from the file in `valuesFileURL`, using the default number of bins.
`void`	`computeDistribution(int binCount)` Computes the empirical distribution using values from the file in `valuesFileURL` and `binCount` bins.
`void`	`fill(double[] values)` Fills the input array with values generated using getNext() repeatedly.
`double[]`	`fill(int length)` Returns an array of length `length` with values generated using getNext() repeatedly.
`EmpiricalDistribution`	`getEmpiricalDistribution()` Returns the `EmpiricalDistribution` used when operating in 0.
`int`	`getMode()` Returns the data generation mode.
`double`	`getMu()` Returns the mean used when operating in `GAUSSIAN_MODE`, `EXPONENTIAL_MODE` or `UNIFORM_MODE`.
`double`	`getNext()` Returns the next generated value, generated according to the mode value (see MODE constants).
`double`	`getSigma()` Returns the standard deviation used when operating in `GAUSSIAN_MODE`.
`URL`	`getValuesFileURL()` Returns the URL for the file used to build the empirical distribution when using `DIGEST_MODE`.
`void`	`reSeed(long seed)` Reseeds the random data generator.
`void`	`resetReplayFile()` Resets REPLAY_MODE file pointer to the beginning of the `valuesFileURL`.
`void`	`setMode(int mode)` Sets the data generation mode.
`void`	`setMu(double mu)` Sets the `mean` used in data generation.
`void`	`setSigma(double sigma)` Sets the `standard deviation` used in `GAUSSIAN_MODE`.
`void`	`setValuesFileURL(String url)` Sets the `values file URL` using a string URL representation.
`void`	`setValuesFileURL(URL url)` Sets the the `values file URL`.

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

- Field Detail
  - DIGEST_MODE
```
public static final int DIGEST_MODE
```
    Use empirical distribution.
    
    See Also:
    Constant Field Values
  - REPLAY_MODE
```
public static final int REPLAY_MODE
```
    Replay data from valuesFilePath.
    
    See Also:
    Constant Field Values
  - UNIFORM_MODE
```
public static final int UNIFORM_MODE
```
    Uniform random deviates with mean = μ.
    
    See Also:
    Constant Field Values
  - EXPONENTIAL_MODE
```
public static final int EXPONENTIAL_MODE
```
    Exponential random deviates with mean = μ.
    
    See Also:
    Constant Field Values
  - GAUSSIAN_MODE
```
public static final int GAUSSIAN_MODE
```
    Gaussian random deviates with mean = μ, std dev = σ.
    
    See Also:
    Constant Field Values
  - CONSTANT_MODE
```
public static final int CONSTANT_MODE
```
    Always return mu
    
    See Also:
    Constant Field Values
- Constructor Detail
  - ValueServer
```
public ValueServer()
```
    Creates new ValueServer
  - ValueServer
```
@Deprecated
public ValueServer(RandomDataImpl randomData)
```
    Deprecated. use ValueServer(RandomGenerator)
    
    Construct a ValueServer instance using a RandomDataImpl as its source of random data.
    
    Parameters:
    randomData - the RandomDataImpl instance used to source random data
    Since:
    
    3.0
  - ValueServer
```
public ValueServer(RandomGenerator generator)
```
    Construct a ValueServer instance using a RandomGenerator as its source of random data.
    
    Parameters:
    generator - source of random data
    Since:
    
    3.1
- Method Detail
  - getNext
```
public double getNext()
               throws IOException,
                      MathIllegalStateException,
                      MathIllegalArgumentException
```
    Returns the next generated value, generated according to the mode value (see MODE constants).
    
    Returns:
    generated value
    
    Throws:
    
    IOException - in REPLAY_MODE if a file I/O error occurs
    
    MathIllegalStateException - if mode is not recognized
    
    MathIllegalArgumentException - if the underlying random generator thwrows one
  - fill
```
public void fill(double[] values)
          throws IOException,
                 MathIllegalStateException,
                 MathIllegalArgumentException
```
    Fills the input array with values generated using getNext() repeatedly.
    
    Parameters:
    values - array to be filled
    
    Throws:
    
    IOException - in REPLAY_MODE if a file I/O error occurs
    
    MathIllegalStateException - if mode is not recognized
    
    MathIllegalArgumentException - if the underlying random generator thwrows one
  - fill
```
public double[] fill(int length)
              throws IOException,
                     MathIllegalStateException,
                     MathIllegalArgumentException
```
    Returns an array of length length with values generated using getNext() repeatedly.
    
    Parameters:
    length - length of output array
    
    Returns:
    array of generated values
    
    Throws:
    
    IOException - in REPLAY_MODE if a file I/O error occurs
    
    MathIllegalStateException - if mode is not recognized
    
    MathIllegalArgumentException - if the underlying random generator thwrows one
  - computeDistribution
```
public void computeDistribution()
                         throws IOException,
                                ZeroException,
                                NullArgumentException
```
    Computes the empirical distribution using values from the file in valuesFileURL, using the default number of bins.
    valuesFileURL must exist and be readable by *this at runtime.
    
    This method must be called before using getNext() with mode = DIGEST_MODE
    
    Throws:
    
    IOException - if an I/O error occurs reading the input file
    
    NullArgumentException - if the valuesFileURL has not been set
    
    ZeroException - if URL contains no data
  - computeDistribution
```
public void computeDistribution(int binCount)
                         throws NullArgumentException,
                                IOException,
                                ZeroException
```
    Computes the empirical distribution using values from the file in valuesFileURL and binCount bins.
    valuesFileURL must exist and be readable by this process at runtime.
    
    This method must be called before using getNext() with mode = DIGEST_MODE
    
    Parameters:
    binCount - the number of bins used in computing the empirical distribution
    
    Throws:
    
    NullArgumentException - if the valuesFileURL has not been set
    
    IOException - if an error occurs reading the input file
    
    ZeroException - if URL contains no data
  - getMode
```
public int getMode()
```
    Returns the data generation mode. See the class javadoc for description of the valid values of this property.
    
    Returns:
    Value of property mode.
  - setMode
```
public void setMode(int mode)
```
    Sets the data generation mode.
    
    Parameters:
    mode - New value of the data generation mode.
  - getValuesFileURL
```
public URL getValuesFileURL()
```
    Returns the URL for the file used to build the empirical distribution when using DIGEST_MODE.
    
    Returns:
    Values file URL.
  - setValuesFileURL
```
public void setValuesFileURL(String url)
                      throws MalformedURLException
```
    Sets the values file URL using a string URL representation.
    
    Parameters:
    url - String representation for new valuesFileURL.
    
    Throws:
    
    MalformedURLException - if url is not well formed
  - setValuesFileURL
```
public void setValuesFileURL(URL url)
```
    Sets the the values file URL.
    The values file must be an ASCII text file containing one valid numeric entry per line.
    
    Parameters:
    url - URL of the values file.
  - getEmpiricalDistribution
```
public EmpiricalDistribution getEmpiricalDistribution()
```
    Returns the EmpiricalDistribution used when operating in 0.
    
    Returns:
    EmpircalDistribution built by computeDistribution()
  - resetReplayFile
```
public void resetReplayFile()
                     throws IOException
```
    Resets REPLAY_MODE file pointer to the beginning of the valuesFileURL.
    
    Throws:
    
    IOException - if an error occurs opening the file
    
    NullPointerException - if the valuesFileURL has not been set.
  - closeReplayFile
```
public void closeReplayFile()
                     throws IOException
```
    Closes valuesFileURL after use in REPLAY_MODE.
    
    Throws:
    
    IOException - if an error occurs closing the file
  - getMu
```
public double getMu()
```
    Returns the mean used when operating in GAUSSIAN_MODE, EXPONENTIAL_MODE or UNIFORM_MODE. When operating in CONSTANT_MODE, this is the constant value always returned. Calling computeDistribution() sets this value to the overall mean of the values in the values file.
    
    Returns:
    Mean used in data generation.
  - setMu
```
public void setMu(double mu)
```
    Sets the mean used in data generation. Note that calling this method after computeDistribution() has been called will have no effect on data generated in DIGEST_MODE.
    
    Parameters:
    mu - new Mean value.
  - getSigma
```
public double getSigma()
```
    Returns the standard deviation used when operating in GAUSSIAN_MODE. Calling computeDistribution() sets this value to the overall standard deviation of the values in the values file. This property has no effect when the data generation mode is not GAUSSIAN_MODE.
    
    Returns:
    Standard deviation used when operating in GAUSSIAN_MODE.
  - setSigma
```
public void setSigma(double sigma)
```
    Sets the standard deviation used in GAUSSIAN_MODE.
    
    Parameters:
    sigma - New standard deviation.
  - reSeed
```
public void reSeed(long seed)
```
    Reseeds the random data generator.
    
    Parameters:
    seed - Value with which to reseed the RandomDataImpl used to generate random data.

Class ValueServer

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

DIGEST_MODE

REPLAY_MODE

UNIFORM_MODE

EXPONENTIAL_MODE

GAUSSIAN_MODE

CONSTANT_MODE

Constructor Detail

ValueServer

ValueServer

ValueServer

Method Detail

getNext

fill

fill

computeDistribution

computeDistribution

getMode

setMode

getValuesFileURL

setValuesFileURL

setValuesFileURL

getEmpiricalDistribution

resetReplayFile

closeReplayFile

getMu

setMu

getSigma

setSigma

reSeed