mHP.b {ASSISTant} | R Documentation |

## Compute the efficacy boundary (modified Haybittle-Peto) for the first two stages

### Description

Compute the efficacy boundary (modified Haybittle-Peto) for the first two stages

### Usage

```
mHP.b(prevalence, N, cov.J, mu.prime, Sigma.prime, alpha, btilde, theta)
```

### Arguments

`prevalence` |
the vector of prevalences between 0 and 1 summing
to 1. |

`N` |
a three-vector of total sample size at each stage |

`cov.J` |
the 3 x 3 covariance matrix for Z_J at each of the three stages |

`mu.prime` |
a list of |

`Sigma.prime` |
a list of |

`alpha` |
the amount of type I error to spend |

`btilde` |
the futility boundary |

`theta` |
the effect size on the probability scale |

*ASSISTant*version 1.4.3 Index]