TITLE(Logistic @@ The Logistic Distribution)
USAGE(
dlogis(x, location, scale=1)
plogis(q, location, scale=1)
qlogis(p, location, scale=1)
rlogis(n, location, scale=1)
)
ALIAS(dlogis)
ALIAS(plogis)
ALIAS(qlogis)
ALIAS(rlogis)
DESCRIPTION(
These functions provide information about the logistic distribution
with parameters LANG(location) and LANG(scale).  LANG(dlogis) gives 
the density, LANG(plogis) gives the distribution function
LANG(qlogis) gives the quantile function and LANG(rlogis) generates
random deviates.
PARA
The Logistic distribution with LANG(location) EQN(a) and LANG(scale) EQN(b)
has density
DEQN(f(x) = OVER(1 @@ b)
OVER(SUP(e@@(x-a)/b) @@
SUP(PAREN( 1 + SUP(e@@(x-a)/b)))@@2).
@@
f(x) = 1/b exp((x-a)/b) (1 + exp((x-a)/b))^-2.)
)
EXAMPLES(
x <- 0:4
paste(dlogis(x, loc = 0)) == paste(exp(x) * (1 + exp(x))^-2)
)
KEYWORD(distribution)
