Abrem: Create an 'abrem' Object for Lifetime and Reliability...
In abrem: Abernethy Reliability Methods

Description Usage Arguments Details Value Author(s) See Also Examples

This function creates an object of class "abrem" for further processing by the other functions of abrem.

1	Abrem(x,...)

x

Either a dataframe containing at least $time and $event columns, or a vector of class "numeric" or "integer" with (life-)time observations.

See section "Details" for other data passing arguments.

...

Graphical options for plotting the abrem object; see section "Details".

There are several methods to passing arguments for building an abrem object.

When a single unnamed vector of class "numeric" or "integer" is supplied, it is treated as a vector of (life-)time observations.
If argument time or fail is provided, it is treated as a vector of (life-)time observations. Take care NOT to supply both time and fail in the same function call.
If argument event is provided, it is treated as a vector of event indicators with possible values of 0 and 1. See section "Value" for more details on event vectors.
If argument susp is provided, it is treated as a vector of right-censored (life-)time observations (also called suspended observations or suspensions). In that case, argument time or fail is mandatory and is treated as a vector of failure times.
If argument x is of class "data.frame", then it should al least contain $time and $event columns. Additional columns in the dataframe will be reused in the abrem object, allowing for extra information like serial numbers to be included (see section "Examples").

Note that is is currently allowed to have NA values in the time argument. In that case, the vector is expected to be ordered and no ordering will be applied by Abrem. This feature is useful in combination with the output of params.to.ob.

Abrem always generates (probability) plot positions for graphically displaying the (life-)time observations and for (possible) later usage by abrem.fit. The type of plot positions is controlled with the pp argument. See options.abrem for more details.

Additionally, one can supply any options available from options.abrem, such as col or is.plot.legend. Some of these options will be used when plotting the (life-)time observations using plot.abrem. Subsequent calls to abrem.fit and abrem.conf will inherit these options.

A named list of class "abrem". The first list item ($data) is a dataframe with at least three columns:

$time: An ordered vector with (life-)time observations.
$event: A vector of class "numeric" with right-censoring indicators. Values of 1 mean "dead" or "failed" while 0 mean "alive" or "right-censored"/"suspended" observations. This censoring indicator scheme is modeled after the Surv function of the survival package.
$rank. ...: Depending on the argument pp (either passed as an argument or taken from options.abrem), a vector of class "numeric" with exact median ranks ($rank.median) or Benard's approximate median ranks ($rank.benard).

Jurgen Symynck jusy@openreliability.org

options.abrem

## These code lines all generate the same object ##
Abrem(c(500,1200,900,1300,510))
Abrem(time=c(500,1200,900,1300,510))
Abrem(time=c(500,1200,900,1300,510),event=c(1,1,1,1,1))
Abrem(fail=c(500,1200,900,1300,510))
Abrem(fail=c(500,1200,900,1300,510),susp=c())
da1 <- data.frame(
    serial=c("S12","S16","S17","S3","S5"),
    time=c(500,1200,900,1300,510),
    event=c(1,1,1,1,1))
Abrem(da1,label="complete dataset",pch=1)
da1 <- Abrem(da1,label="complete dataset",pch=3,col="orange3")

## Generate a similar dataset, but with suspensions ##
Abrem(time=c(500,1200,900,1300,510),event=c(1,1,1,0,0))
Abrem(data.frame(time=c(500,1200,900,1300,510),event=c(1,1,1,0,0)))
Abrem(fail=c(500,1200,900),susp=c(1300,510))
Abrem(time=c(500,1200,900),susp=c(1300,510))
da3 <- Abrem(fail=c(500,1200,900,1300,510),
    event=c(1,1,1,0,0),label="censored dataset",pch=1,col="blue")

## plot datasets ##
plot.abrem(list(da1,da3))