qbs {bs} | R Documentation |
Quantile function of the BSD with shape parameter alpha and scale parameter beta.
qbs(p, alpha = 1, beta = 1, lower.tail = TRUE, log.p = FALSE)
p |
Vector of probabilities. |
alpha |
Shape parameter. |
beta |
Scale parameter. |
lower.tail |
Logical; if TRUE (default), probabilities are P[X <= x], otherwise, P[X > x]. |
log.p |
Logical; if TRUE, probabilities p are given as log(p). |
Birnbaum and Saunders (1969) proposed the two-parameter Birnbaum-Saunders distribution with density
f_{T}(t) = frac{1}{sqrt{2π}} exp<=ft[-frac{1}{2α^{2}} (frac{t}{β}+frac{β}{t}-2) right] frac{t^{-frac{3}{2}} (t+β)}{2αsqrt{β}}; t>0, α > 0, β > 0,
as a failure time distribution for fatigue failure caused under cyclic loading. The parameters alpha and bata are the shape and the scale parameters, respectively. In their derivation, it was assumed that the failure is due to the development and growth of a dominant crack.
qbs()
gives the qf of an BSD.
Víctor Leiva <victor.leiva@uv.cl>, Hugo Hernández <hugo.hernande@msn.com>, and Marco Riquelme <mriquelm@ucm.cl>.
Birnbaum, Z. W. and Saunders, S. C. (1969). A new family of life distributions. J. Appl. Probab. 6(2): 637-652.
## Load package library(bs) ## cuantil function for p=0.5 in the BSD ## with parameters alpha=0.5 y beta=1.0. pbs(0.5,alpha=0.5,beta=1.0,log=FALSE)