Distribution function and quantile function
of the generalized logistic distribution.
Usage
cdfglo(x, para = c(0, 1, 0))
quaglo(f, para = c(0, 1, 0))
Arguments
x
Vector of quantiles.
f
Vector of probabilities.
para
Numeric vector containing the parameters of the distribution,
in the order xi, alpha, k (location, scale, shape).
Details
The generalized logistic distribution with
location parameter xi,
scale parameter alpha and
shape parameter k has distribution function
F(x)= 1 / (1+exp(-y))
where
y = (-1/k) log(1-k(x-xi)/alpha) ,
with x bounded by xi+alpha/k
from below if k<0 and from above if k>0,
and quantile function
x(F) = xi + alpha (1 - ((1-F)/F)^k) / k .
The logistic distribution is the special case k=0.
Value
cdfglo gives the distribution function;
quaglo gives the quantile function.
Note
The functions expect the distribution parameters in a vector,
rather than as separate arguments as in the standard R
distribution functions pnorm, qnorm, etc.
See Also
cdfkap for the kappa distribution,
which generalizes the generalized logistic distribution.
Examples
# Random sample from the generalized logistic distribution
# with parameters xi=0, alpha=1, k=-0.5.
quaglo(runif(100), c(0,1,-0.5))