| littlewood.verall.plot {Reliability} | R Documentation |
littlewood.verall.plot plots the mean value function for the Littlewood-Verall
model and the raw data into one window.
littlewood.verall.plot(theta0, theta1, rho, t, linear = T, xlab = "time",
ylab = "Cumulated failures and estimated mean value function",
main = NULL)
theta0 |
parameter value for theta0 |
theta1 |
parameter value for theta1 |
rho |
parameter value for rho |
t |
time between failure data |
linear |
logical. Should the linear or the quadratic form of the mean value
function for the Littlewood-Verrall model be used of computation?
If TRUE, which is the default, the linear form of the mean
value function is used. |
xlab |
a title for the x axis |
ylab |
a title for the y axis |
main |
an overall title for the plot |
This function gives a plot of the mean value function for the Littlewood-Verall
model. Here the estimated parameter values for theta0, theta1 and
theta, which are obtained by using littlewood.verall, can
be put in. Internally the functions mvf.ver.lin or mvf.ver.quad
are used to get the mean value function for the Littlewood-Verall model. This depends
on the calibration, if the linear or the quadratic form of the mean value function
for the Littlewood-Verall model should be used.
A graph of the mean value function for the Littlewood-Verall model and of the raw data.
Andreas Wittmann andreas_wittmann@gmx.de
J.D. Musa, A. Iannino, and K. Okumoto. Software Reliability: Measurement, Prediction, Application. McGraw-Hill, 1987.
Michael R. Lyu. Handbook of Software Realibility Engineering. IEEE Computer Society Press, 1996. http://www.cse.cuhk.edu.hk/~lyu/book/reliability/
littlewood.verall, mvf.ver.lin, mvf.ver.quad
# time between-failure-data from DACS Software Reliability Dataset
# homepage, see system code 1. Number of failures is 136.
t <- c(3, 30, 113, 81, 115, 9, 2, 20, 20, 15, 138, 50, 77, 24,
108, 88, 670, 120, 26, 114, 325, 55, 242, 68, 422, 180,
10, 1146, 600, 15, 36, 4, 0, 8, 227, 65, 176, 58, 457,
300, 97, 263, 452, 255, 197, 193, 6, 79, 816, 1351, 148,
21, 233, 134, 357, 193, 236, 31, 369, 748, 0, 232, 330,
365, 1222, 543, 10, 16, 529, 379, 44, 129, 810, 290, 300,
529, 281, 160, 828, 1011, 445, 296, 1755, 1064, 1783,
860, 983, 707, 33, 868, 724, 2323, 2930, 1461, 843, 12,
261, 1800, 865, 1435, 30, 143, 108, 0, 3110, 1247, 943,
700, 875, 245, 729, 1897, 447, 386, 446, 122, 990, 948,
1082, 22, 75, 482, 5509, 100, 10, 1071, 371, 790, 6150,
3321, 1045, 648, 5485, 1160, 1864, 4116)
theta0 <- littlewood.verall(t, linear = TRUE)$theta0
theta1 <- littlewood.verall(t, linear = TRUE)$theta1
rho <- littlewood.verall(t, linear = TRUE)$rho
littlewood.verall.plot(theta0, theta1, rho, t, linear = TRUE,
xlab = "time (in seconds)", main = "Littlewood-Verall model (linear)")
## Not run:
## theta0 <- littlewood.verall(t, linear = FALSE)$theta0
## theta1 <- littlewood.verall(t, linear = FALSE)$theta1
## rho <- littlewood.verall(t, linear = FALSE)$rho
## littlewood.verall.plot(theta0, theta1, rho, t, linear = FALSE,
## xlab = "time (in seconds)", main = "Littlewood-Verall modell (quadratic)")
## End(Not run)