qig {ig} | R Documentation |
Quantile function for the IGDT with mean mu, scale parameter lambda and associated kernel g.
qig(p, mu = 1, lambda = 1, kernel = "normal", parameter.nu = 1, lower.tail = TRUE, log.p = FALSE)
p |
Vector of quantiles. |
mu |
Mean. |
lambda |
Scale parameter. |
kernel |
Kernel of the pdf of the associated symmetrical distribution by means of which the IGTD is obtained. The kernels: "Laplace" , "logistic" , "normal" and "t" are available. |
parameter.nu |
Additional parameter of the IGTD when the t kernel is used. |
lower.tail |
Logical; if TRUE (default), probabilities are P[X <= x], otherwise, P[X > x]. |
log.p |
Logical; if TRUE, probabilities pr are given as log(pr). |
Unfortunately, it is not possible to find the qf of the IGTD in a closed analytical form, so these values must be obtained by numerical methods.
qig()
gives the qf of an IGTD.
Víctor Leiva <victor.leiva@uv.cl>, Hugo Hernández <hugo.hernandez@msn.com>, and Antonio Sanhueza <asanhue@ufro.cl>.
Sanhueza, A., Leiva, V. and Balakrishnan, N. (2007). A new class of inverse Gaussian type distributions. Metrika (in press).
## Compute the 50 ## of the IGT with mu=1, lambda=1 and kernel="normal" x <- 0.5 q <- qig(0.5,mu=1.0,lambda=1.0,kernel="normal") q