# Fertilizer Data

### Description

A small data set on the use of fertilizer (x) in relation to the amount of grain (y1) and straw (y2) produced.

### Usage

1 |

### Format

A data frame with 8 observations on the following 3 variables.

`grain`

amount of grain produced

`straw`

amount of straw produced

`fertilizer`

amount of fertilizer applied

### Details

The first observation is an obvious outlier and influential observation.

### Source

Anderson, T. W. (1984).
*An Introduction to Multivariate Statistical Analysis*,
New York: Wiley, p. 369.

### References

Hossain, A. and Naik, D. N. (1989).
Detection of influential observations in multivariate regression.
*Journal of Applied Statistics*, 16 (1), 25-37.

### Examples

1 2 3 4 5 6 7 8 9 10 11 12 13 14 | ```
data(Fertilizer)
# simple plots
plot(Fertilizer, col=c('red', rep("blue",7)), cex=c(2,rep(1.2,7)), pch=as.character(1:8))
biplot(prcomp(Fertilizer))
#fit mlm
mod <- lm(cbind(grain, straw) ~ fertilizer, data=Fertilizer)
Anova(mod)
# influence plots (m=1)
influencePlot(mod)
influencePlot(mod, type='LR')
influencePlot(mod, type='stres')
``` |

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