Description Usage Arguments Value References Examples

This function calculates the sample size for given type-I and type-II error probabilities using Noether's formula. If ties are present then prior information is needen.

1 | ```
WMWssp_noether(alpha, power, t, p, x = c(0), ties = FALSE)
``` |

`alpha` |
two sided type I error rate |

`power` |
power: detect a relative effect p at least with the specified power |

`t` |
proportion of subjects in the first group (between 0 and 1) |

`p` |
relative effect |

`x` |
prior information is only needed in case of ties |

`ties` |
TRUE if ties are possible (non continuous distribution), otherwise FALSE |

Returns an object from class WMWssp containing

`result` |
A dataframe with the results. |

`t` |
The allocation rate which was used. |

`alpha` |
The type-I error rate which was used. |

`power` |
The power which was used. |

`N` |
The sample size needed. |

Noether, G. E. (1987). Sample Size Determination for Some Common Nonparametric Tests. Journal of the American Statistical Association 85, 645.647.

1 2 3 4 5 6 7 8 9 | ```
# Prior information for the reference group
x <- c(315,375,356,374,412,418,445,403,431,410,391,475,379)
# generate data for treatment group based on a shift effect
y <- x - 20
# this data leads to a relative effect of p = 0.349
# calculate sampe size for a balanced design
ssp <- WMWssp_noether(alpha = 0.05, power = 0.8, t =1/2, p = 0.349)
summary(ssp)
``` |

Embedding an R snippet on your website

Add the following code to your website.

For more information on customizing the embed code, read Embedding Snippets.