public class Logistic extends java.lang.Object implements UnivariateDifferentiableFunction, DifferentiableUnivariateFunction
Modifier and Type | Class and Description |
---|---|
static class |
Logistic.Parametric
Parametric function where the input array contains the parameters of
the
logistic function , ordered as follows:
k
m
b
q
a
n
|
Modifier and Type | Field and Description |
---|---|
private double |
a
Lower asymptote.
|
private double |
b
Growth rate.
|
private double |
k
Upper asymptote.
|
private double |
m
Abscissa of maximum growth.
|
private double |
oneOverN
Parameter that affects near which asymptote maximum growth occurs.
|
private double |
q
Parameter that affects the position of the curve along the ordinate axis.
|
Constructor and Description |
---|
Logistic(double k,
double m,
double b,
double q,
double a,
double n) |
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.
|
private static double |
value(double mMinusX,
double k,
double b,
double q,
double a,
double oneOverN) |
private final double a
private final double k
private final double b
private final double oneOverN
private final double q
private final double m
public Logistic(double k, double m, double b, double q, double a, double n) throws NotStrictlyPositiveException
k
- If b > 0
, value of the function for x going towards +∞.
If b < 0
, value of the function for x going towards -∞.m
- Abscissa of maximum growth.b
- Growth rate.q
- Parameter that affects the position of the curve along the
ordinate axis.a
- If b > 0
, value of the function for x going towards -∞.
If b < 0
, value of the function for x going towards +∞.n
- Parameter that affects near which asymptote the maximum
growth occurs.NotStrictlyPositiveException
- if n <= 0
.public double value(double x)
value
in interface UnivariateFunction
x
- Point at which the function value should be computed.@Deprecated public UnivariateFunction derivative()
value(DerivativeStructure)
derivative
in interface DifferentiableUnivariateFunction
private static double value(double mMinusX, double k, double b, double q, double a, double oneOverN)
mMinusX
- m - x
.k
- k
.b
- b
.q
- q
.a
- a
.oneOverN
- 1 / n
.public DerivativeStructure value(DerivativeStructure t)
UnivariateDifferentiableFunction
classes compute both the
value and the first derivative of the function.
value
in interface UnivariateDifferentiableFunction
t
- function input valueCopyright (c) 2003-2016 Apache Software Foundation