summary.manova {stats} R Documentation

## Summary Method for Multivariate Analysis of Variance

### Description

A `summary` method for class `"manova"`.

### Usage

```## S3 method for class 'manova':
summary(object,
test = c("Pillai", "Wilks", "Hotelling-Lawley", "Roy"),
intercept = FALSE, ...)
```

### Arguments

 `object` An object of class `"manova"` or an `aov` object with multiple responses. `test` The name of the test statistic to be used. Partial matching is used so the name can be abbreviated. `intercept` logical. If `TRUE`, the intercept term is included in the table. `...` further arguments passed to or from other methods.

### Details

The `summary.manova` method uses a multivariate test statistic for the summary table. Wilks' statistic is most popular in the literature, but the default Pillai-Bartlett statistic is recommended by Hand and Taylor (1987).

### Value

A list with components

 `SS` A named list of sums of squares and product matrices. `Eigenvalues` A matrix of eigenvalues. `stats` A matrix of the statistics, approximate F value, degrees of freedom and P value.

### References

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

Hand, D. J. and Taylor, C. C. (1987) Multivariate Analysis of Variance and Repeated Measures. Chapman and Hall.

`manova`, `aov`

### Examples

```## Example 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 <- factor(gl(2,10), labels=c("Low", "High"))
additive <- factor(gl(2, 5, len=20), labels=c("Low", "High"))

fit <- manova(Y ~ rate * additive)
summary.aov(fit)           # univariate ANOVA tables
summary(fit, test="Wilks") # ANOVA table of Wilks' lambda
```

[Package stats version 2.1.0 Index]