Logis-class {distr}R Documentation

Class "Logis"

Description

The Logistic distribution with location = m, by default = 0, and scale = s, by default = 1, has distribution function

p(x) = 1 / (1 + exp(-(x-m)/s))

and density

d(x) = 1/s exp((x-m)/s) (1 + exp((x-m)/s))^-2.

It is a long-tailed distribution with mean m and variance pi^2 /3 s^2. C.f. rlogis

Objects from the Class

Objects can be created by calls of the form Logis(location, scale). This object is a logistic distribution.

Slots

img:
Object of class "Reals": The space of the image of this distribution has got dimension 1 and the name "Real Space".
param:
Object of class "LogisParameter": the parameter of this distribution (location and scale), declared at its instantiation
r:
Object of class "function": generates random numbers (calls function rlogis)
d:
Object of class "function": density function (calls function dlogis)
p:
Object of class "function": cumulative function (calls function plogis)
q:
Object of class "function": inverse of the cumulative function (calls function qlogis)
.withArith:
logical: used internally to issue warnings as to interpretation of arithmetics
.withSim:
logical: used internally to issue warnings as to accuracy
.logExact:
logical: used internally to flag the case where there are explicit formulae for the log version of density, cdf, and quantile function
.lowerExact:
logical: used internally to flag the case where there are explicit formulae for the lower tail version of cdf and quantile function

Extends

Class "AbscontDistribution", directly.
Class "UnivariateDistribution", by class "AbscontDistribution".
Class "Distribution", by class "AbscontDistribution".

Methods

initialize
signature(.Object = "Logis"): initialize method
location
signature(object = "Logis"): returns the slot location of the parameter of the distribution
location<-
signature(object = "Logis"): modifies the slot location of the parameter of the distribution
scale
signature(object = "Logis"): returns the slot scale of the parameter of the distribution
scale<-
signature(object = "Logis"): modifies the slot scale of the parameter of the distribution
*
signature(e1 = "Logis", e2 = "numeric")
+
signature(e1 = "Logis", e2 = "numeric"): For the logistic location scale family we use its closedness under affine linear transformations.

Author(s)

Thomas Stabla statho3@web.de,
Florian Camphausen fcampi@gmx.de,
Peter Ruckdeschel Peter.Ruckdeschel@itwm.fraunhofer.de,
Matthias Kohl Matthias.Kohl@stamats.de

See Also

LogisParameter-class AbscontDistribution-class Reals-class rlogis

Examples

L <- Logis(location = 1,scale = 1)
# L is a logistic distribution with  location = 1 and scale = 1.
r(L)(1) # one random number generated from this distribution, e.g. 5.87557
d(L)(1) # Density of this distribution is 0.25 for x = 1.
p(L)(1) # Probability that x < 1 is 0.5.
q(L)(.1) # Probability that x < -1.197225 is 0.1.
location(L) # location of this distribution is 1.
location(L) <- 2 # location of this distribution is now 2.

[Package distr version 2.1.1 Index]