distr (version 2.3.1)

Exp-class: Class "Exp"

Description

The exponential distribution with rate $\lambda$ has density $$f(x) = \lambda {e}^{- \lambda x}$$ for $x \ge 0$. C.f. rexp

Objects from the Class

Objects can be created by calls of the form Exp(rate). This object is an exponential distribution.

Extends

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

Is-Relations

By means of setIs, R ``knows'' that a distribution object obj of class "Exp" also is a Gamma distribution with parameters shape = 1, scale = 1/rate(obj) and a Weibull distribution with parameters shape = 1, scale = 1/rate(obj)

concept

• Exponential distribution
• memoryless distribution
• absolutely continuous distribution
• S4 distribution class
• generating function

See Also

ExpParameter-class AbscontDistribution-class Reals-class rexp

Examples

E <- Exp(rate = 1) # E is a exp distribution with rate = 1.
r(E)(1) # one random number generated from this distribution, e.g. 0.4190765
d(E)(1) # Density of this distribution is 0.3678794 for x = 1.
p(E)(1) # Probability that x < 1 is 0.6321206.
q(E)(.1) # Probability that x < 0.1053605 is 0.1.
rate(E) # rate of this distribution is 1.
rate(E) <- 2 # rate of this distribution is now 2.
is(E, "Gammad") # yes
as(E,"Gammad")
is(E, "Weibull") 
E+E+E ###  a Gammad -distribution
2*E+Gammad(scale=1)