psi21 {bs} | R Documentation |
Several data sets related to the BSD are available in the bs package, which have been taken from the literature on this topic.
data(psi21)
A vector containing 101 observations.
psi21, psi26 and psi31 were taken from Birnbaum and Saunders (1969), who reported fatigue life data correspond to the cycles (times 10^{-3}) of aluminum specimens of type 6061-T6. These specimens were cut in a parallel angle to the direction of rotation and oscillating at 18 cycles per seconds. They were exposed to a pressure with maximum stress of 21,000, 26,000, and 31,000 psi (pounds per square inch), for n = 101, 102, and 101 specimens, respectively.
Birnbaum, Z. W. and Saunders, S. C. (1969). Estimation for a family of life distributions with applications to fatigue. J. Appl. Probab. 6(2): 328-347.
## Load data sets data(psi21) ## Histogram for psi21 hist(psi21)