# Plastic: Plastic Film Data In heplots: Visualizing Hypothesis Tests in Multivariate Linear Models

## Description

An experiment was conducted to determine the optimum conditions for extruding plastic film. Three responses were measured in relation to two factors, rate of extrusion and amount of an additive.

## Usage

 `1` ```data(Plastic) ```

## Format

A data frame with 20 observations on the following 5 variables.

`tear`

a numeric vector: tear resistance

`gloss`

a numeric vector: film gloss

`opacity`

a numeric vector: film opacity

`rate`

a factor representing change in the rate of extrusion with levels `Low` (-10%), `High` (10%)

`additive`

a factor with levels `Low` (1.0%), `High` (1.5%)

## Source

Johnson, R.A. & Wichern, D.W. (1992). Applied Multivariate Statistical Analysis, 3rd ed., Prentice-Hall. Example 6.12 (p. 266).

## References

Krzanowski, W. J. (1988). Principles of Multivariate Analysis. A User's Perspective. Oxford. (p. 381)

## Examples

 ```1 2 3 4 5``` ```str(Plastic) plastic.mod <- lm(cbind(tear, gloss, opacity) ~ rate*additive, data=Plastic) Anova(plastic.mod) pairs(plastic.mod) ```

### Example output

```Loading required package: car
'data.frame':	20 obs. of  5 variables:
\$ tear    : num  6.5 6.2 5.8 6.5 6.5 6.9 7.2 6.9 6.1 6.3 ...
\$ gloss   : num  9.5 9.9 9.6 9.6 9.2 9.1 10 9.9 9.5 9.4 ...
\$ opacity : num  4.4 6.4 3 4.1 0.8 5.7 2 3.9 1.9 5.7 ...
\$ rate    : Factor w/ 2 levels "Low","High": 1 1 1 1 1 1 1 1 1 1 ...
\$ additive: Factor w/ 2 levels "Low","High": 1 1 1 1 1 2 2 2 2 2 ...

Type II MANOVA Tests: Pillai test statistic
Df test stat approx F num Df den Df   Pr(>F)
rate           1   0.61814   7.5543      3     14 0.003034 **
additive       1   0.47697   4.2556      3     14 0.024745 *
rate:additive  1   0.22289   1.3385      3     14 0.301782
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
```

heplots documentation built on Oct. 7, 2021, 1:07 a.m.