# Plot for Group Sequential Boundaries

### Description

Plot of the sequential boundaries for objects of class '"bounds"' or '"drift"'.

### Usage

1 2 3 4 |

### Arguments

`x` |
an object of class '"bounds"' or '"drift"'. |

`main` |
an overall title for the plot: see |

`xlab` |
a title for the x axis: see |

`ylab` |
a title for the y axis: see |

`...` |
graphical parameters can be given as arguments to |

### Author(s)

Charlie Casper charlie.casper@hsc.utah.edu and Oscar A. Perez

### References

Reboussin, D. M., DeMets, D. L., Kim, K. M., and Lan,
K. K. G. (2000) Computations for group sequential boundaries using the
Lan-DeMets spending function method. *Controlled Clinical Trials*,
21:190-207.

Fortran program 'ld98' by the same authors as above.

DeMets, D. L. and Lan, K. K. G. (1995) *Recent Advances in Clinical
Trial Design and Analysis*, Thall, P. F. (ed.). Boston: Kluwer
Academic Publishers.

Lan, K. K. G. and DeMets, D. L. (1983) Discrete sequential boundaries
for clinical trials. *Biometrika*, 70:659-63.

### See Also

Generic functions `summary.bounds`

and `summary.drift`

,
`bounds`

to calculate sequential boundaries,
`drift`

for exit probabilities given boundaries or drift (effect) or confidence interval given power.

### Examples

1 | ```
## See 'bounds' or 'drift'.
``` |