jsat.math.decayrates

Class LinearDecay

java.lang.Object

jsat.math.decayrates.LinearDecay

All Implemented Interfaces:

Serializable, DecayRate, Parameterized

public class LinearDecay
extends Object
implements DecayRate, Parameterized

The Linear Decay requires the maximum time step to be explicitly known ahead of time. Provided either in the call to rate(double, double, double), or internal by setMinRate(double).

The Linear Decay will decay at a constant rate / slope from the initial value until the specified setMinRate(double) is reached.

Author:

Edward Raff

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
LinearDecay() Creates a new linear decay that goes down to 1e-4 after 100,000 units of time
LinearDecay(double min, double maxTime) Creates a new Linear Decay Note that when using rate(double, double, double), the maxTime is always superceded by the value given to the function.

Method Summary

Modifier and Type	Method and Description
DecayRate	clone()
double	getMaxTime() Returns the maximum time to use in the rate decay
double	getMinRate() Returns the minimum value to return from he rate methods
Parameter	getParameter(String paramName) Returns the parameter with the given name.
List<Parameter>	getParameters() Returns the list of parameters that can be altered for this learner.
double	rate(double time, double initial) Decays the initial value over time.
double	rate(double time, double maxTime, double initial) Decays the initial value over time.
void	setMaxTime(double maxTime) Sets the maximum amount of time to allow in the rate decay.
void	setMinRate(double min) Sets the minimum learning rate to return
String	toString()

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

LinearDecay

public LinearDecay()

Creates a new linear decay that goes down to 1e-4 after 100,000 units of time

LinearDecay

public LinearDecay(double min,
                   double maxTime)

Creates a new Linear Decay

Note that when using rate(double, double, double), the maxTime is always superceded by the value given to the function.

Parameters:

min - a value less than the learning rate that, that will be the minimum returned value

maxTime - the maximum amount of time

Method Detail

setMinRate

public void setMinRate(double min)

Sets the minimum learning rate to return

Parameters:

min - the minimum learning rate to return

getMinRate

public double getMinRate()

Returns the minimum value to return from he rate methods

Returns:

the minimum value to return

setMaxTime

public void setMaxTime(double maxTime)

Sets the maximum amount of time to allow in the rate decay. Any time value larger will be treated as the set maximum.

Any calls to rate(double, double, double) will use the value provided in that method call instead.

Parameters:

maxTime - the maximum amount of time to allow

getMaxTime

public double getMaxTime()

Returns the maximum time to use in the rate decay

Returns:

the maximum time to use in the rate decay

rate

public double rate(double time,
                   double maxTime,
                   double initial)

Description copied from interface: DecayRate

Decays the initial value over time.

Specified by:

rate in interface DecayRate

Parameters:

time - the current time through the algorithm in the range [0, maxTime]

maxTime - the maximum time step that will be seen

initial - the initial value

Returns:

the decayed value over time of the initial value

rate

public double rate(double time,
                   double initial)

Description copied from interface: DecayRate

Decays the initial value over time.

Specified by:

rate in interface DecayRate

Parameters:

time - the current time step to return a value for

initial - the initial learning rate

Returns:

the decayed value

clone

public DecayRate clone()

Specified by:

clone in interface DecayRate

Overrides:

clone in class Object

toString

public String toString()

Overrides:

toString in class Object

getParameters

public List<Parameter> getParameters()

Description copied from interface: Parameterized

Returns the list of parameters that can be altered for this learner.

Specified by:

getParameters in interface Parameterized

Returns:

the list of parameters that can be altered for this learner.

getParameter

public Parameter getParameter(String paramName)

Description copied from interface: Parameterized

Returns the parameter with the given name. Two different strings may map to a single Parameter object. An ASCII only string, and a Unicode style string.

Specified by:

getParameter in interface Parameterized

Parameters:

paramName - the name of the parameter to obtain

Returns:

the Parameter in question, or null if no such named Parameter exists.