Description Usage Arguments Value Note Author(s)

View source: R/test_multiContrasts.R

This function tests for significant contrasts between multivariate habitat-means within islands. The procedure is parametric and involves calculation of Wilk's lambda and P-value adjustment.

1 | ```
test_multiContrasts(W, specdata, vars, method = "bonferroni")
``` |

`W` |
A matrix indicating all contrasts to be tested, or a vector if only one contrast. The number of rows is the number of contrasts to test. The number of columns is the number of groups. The matrix/vector is filled with zeros, except for a 1 and a -1 at the position of the groups that are to be contrasted. |

`specdata` |
A data frame containing at least columns for the dependent variables, as well as a column "island" and a column "habitat". |

`vars` |
A character or integer vector. The names, or indices, of the dependent variables in |

`method` |
Correction method for adjusting p-values. |

A data frame with the results of each Wilk's lambda test in rows. In columns,

`hab1`

,`hab2`

Habitats being compared.`Wilks`

Wilk's lambda.`approx.F`

F-value computed from Wilk's lambda.`df1`

,`df2`

Numerator and denominator degrees of freedom of the F distribution.`p.value`

P-value computed from the F-distribution.`p.adj`

Corrected P-value.

The parametric procedure was adapted from Charles Zaiontz's post on multivariate contrast testing in Excel: http://www.real-statistics.com/multivariate-statistics/multivariate-analysis-of-variance-manova/manova-follow-up-contrasts/.

Raphael Scherrer

rscherrer/sagreicolor documentation built on Dec. 26, 2018, 1:15 p.m.

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.