dexp(x, rate=1, scale, log=F) pexp(q, rate=1, scale) qexp(p, rate=1, scale) rexp(n, rate=1, scale, bigdata=F)
bdVector
of quantiles.
Missing values (
NA
s) are allowed.
bdVector
of quantiles.
Missing values (
NA
s) are allowed.
bdVector
of probabilities.
Missing values (
NA
s) are allowed.
length(n)
is larger than 1, then
length(n)
random values are returned.
scale
is supplied
and
rate
is not, then
rate = 1/scale
.
This is ignored if
rate
is supplied.
TRUE
, an object of type
bdVector
is returned.
Otherwise, a
vector
object is returned. This argument can be used only if the bigdata library section has been loaded.
TRUE
,
dexp
will return
the log of the density, not the density itself.
dexp
),
probability (
pexp
),
quantile (
qexp
), or
random sample (
rexp
)
for the standard exponential distribution.
rexp
causes creation of the dataset
.Random.seed
if it does
not already exist, otherwise its value is updated.
Elements of
q
or
p
that are missing will cause the corresponding elements of the result to be missing.
The exponential distribution, a specialization of the gamma distribution
(see
Gamma
), takes on positive real values. A major use of the exponential
is in life testing. The exponential has the so called "memoryless property"
that the distribution of failure time is the same as the distribution of
failure time conditional on having survived to time t.
A relative of the exponential is the double exponential or
Laplace distribution.
The double exponential is "folded over" so that it is symmetric about zero.
For details on the uniform random number generator implemented in S-PLUS,
see the
set.seed
help file.
Johnson, N. L. and Kotz, S. (1970). Continuous Univariate Distributions, vol. 1 and 2. Houghton-Mifflin, Boston.
values <- seq(0.0001, 6, length=200); bvals <- values[values>qexp(.95)] plot(values, dexp(values), type="l") polygon(c(qexp(.95), bvals, 6), c(0, dexp(bvals), 0)) abline(h=0); abline(v=0)