mvpaircomp {biotools} | R Documentation |

## Multivariate Pairwise Comparisons

### Description

Performs pairwise comparisons of multivariate mean vectors of factor levels, overall or nested.
The tests are run in the same spirt of `summary.manova()`

, based on multivariate statistics such as Pillai's trace
and Wilks' lambda, which can be applied to test multivariate contrasts.

### Usage

```
mvpaircomp(model, factor1, nesting.factor = NULL,
test = "Pillai", adjust = "none", SSPerror = NULL, DFerror = NULL)
## S3 method for class 'mvpaircomp'
print(x, ...)
```

### Arguments

`model` |
a multivariate analysis of variance (MANOVA) model, fitted using |

`factor1` |
a character string indicating a factor declared in the |

`nesting.factor` |
optional; a character string indicating a factor also declared in |

`test` |
a character string indicating the type of multivariate statistics to be calculated to perform the
F-test approximation. Default is |

`adjust` |
a character string indicating the p-value adjustment method for multiple comparisons. Default is |

`SSPerror` |
optional; a numeric matrix representing the residual sum of squares and cross-products, to be used to compute the multivariate statistics. |

`DFerror` |
optional; a numeric value representing the residual degrees of freedom, to be used to compute the multivariate statistics. |

`x` |
an object of class |

`...` |
further arguments. |

### Value

An object of class `mvpaircomp`

, a list of

`st` |
an array containing the summary of the multivariate tests. |

`SSPcontrast` |
an array containing p-dimensional square matrices of sum of squares and cross-products of the contrasts. |

`adjust` |
a character string indicating the p-value adjustment method used. |

`fac1` |
a character string indicating the factor being tested. |

`fac2` |
a character string indicating the nesting factor. |

### Author(s)

Anderson Rodrigo da Silva <anderson.agro@hotmail.com>

### References

Krzanowski, W. J. (1988) *Principles of Multivariate Analysis*. A User's Perspective. Oxford.

### See Also

### Examples

```
# Example 1
data(maize)
M <- lm(cbind(NKPR, ED, CD, PH) ~ family + env, data = maize)
anova(M) # MANOVA table
mvpaircomp(M, factor1 = "family", adjust = "bonferroni")
# Example 2 (with nesting factor)
# Data on producing plastic film from Krzanowski (1998, p. 381)
tear <- c(6.5, 6.2, 5.8, 6.5, 6.5, 6.9, 7.2, 6.9, 6.1, 6.3,
6.7, 6.6, 7.2, 7.1, 6.8, 7.1, 7.0, 7.2, 7.5, 7.6)
gloss <- c(9.5, 9.9, 9.6, 9.6, 9.2, 9.1, 10.0, 9.9, 9.5, 9.4,
9.1, 9.3, 8.3, 8.4, 8.5, 9.2, 8.8, 9.7, 10.1, 9.2)
opacity <- c(4.4, 6.4, 3.0, 4.1, 0.8, 5.7, 2.0, 3.9, 1.9, 5.7,
2.8, 4.1, 3.8, 1.6, 3.4, 8.4, 5.2, 6.9, 2.7, 1.9)
Y <- cbind(tear, gloss, opacity)
rate <- gl(2, 10, labels = c("Low", "High"))
additive <- gl(2, 5, length = 20, labels = c("Low", "High"))
fit <- manova(Y ~ rate * additive)
summary(fit, test = "Wilks") # MANOVA table
mvpaircomp(fit, factor1 = "rate", nesting.factor = "additive", test = "Wilks")
mvpaircomp(fit, factor1 = "additive", nesting.factor = "rate", test = "Wilks")
# End (not run)
```

*biotools*version 4.2 Index]