Sigmoid (Apache Commons Math 3.6.1 API)

java.lang.Object
- org.apache.commons.math3.analysis.function.Sigmoid

All Implemented Interfaces:

DifferentiableUnivariateFunction, UnivariateDifferentiableFunction, UnivariateFunction
```
public class Sigmoid
extends Object
implements UnivariateDifferentiableFunction, DifferentiableUnivariateFunction
```
Sigmoid function. It is the inverse of the logit function. A more flexible version, the generalised logistic, is implemented by the Logistic class.

Since:

3.0

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`static class`	`Sigmoid.Parametric` Parametric function where the input array contains the parameters of the `sigmoid function`, ordered as follows: Lower asymptote Higher asymptote

Constructor Summary

Constructors
Constructor and Description
`Sigmoid()` Usual sigmoid function, where the lower asymptote is 0 and the higher asymptote is 1.
`Sigmoid(double lo, double hi)` Sigmoid function.

Method Summary

Methods
Modifier and Type	Method and Description
`UnivariateFunction`	`derivative()` Deprecated. as of 3.1, replaced by `value(DerivativeStructure)`
`DerivativeStructure`	`value(DerivativeStructure t)` Simple mathematical function.
`double`	`value(double x)` Compute the value of the function.

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

- Constructor Detail
  - Sigmoid
```
public Sigmoid()
```
    Usual sigmoid function, where the lower asymptote is 0 and the higher asymptote is 1.
  - Sigmoid
```
public Sigmoid(double lo,
       double hi)
```
    Sigmoid function.
    
    Parameters:
    lo - Lower asymptote.
    hi - Higher asymptote.
- Method Detail
  - derivative
```
@Deprecated
public UnivariateFunction derivative()
```
    Deprecated. as of 3.1, replaced by value(DerivativeStructure)
    
    Returns the derivative of the function
    
    Specified by:
    
    derivative in interface DifferentiableUnivariateFunction
    
    Returns:
    the derivative function
  - value
```
public double value(double x)
```
    Compute the value of the function.
    
    Specified by:
    
    value in interface UnivariateFunction
    
    Parameters:
    x - Point at which the function value should be computed.
    
    Returns:
    the value of the function.
  - value
```
public DerivativeStructure value(DerivativeStructure t)
                          throws DimensionMismatchException
```
    Simple mathematical function.
    UnivariateDifferentiableFunction classes compute both the value and the first derivative of the function.
    
    Specified by:
    
    value in interface UnivariateDifferentiableFunction
    
    Parameters:
    t - function input value
    
    Returns:
    function result
    
    Throws:
    
    DimensionMismatchException - if t is inconsistent with the function's free parameters or order
    Since:
    
    3.1

Class Sigmoid

Nested Class Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

Sigmoid

Sigmoid

Method Detail

derivative

value

value