Phosphorus Content Data

Description

This dataset investigates the effect from inorganic and organic Phosphorus in the soil upon the phosphorus content of the corn grown in this soil, from Prescott (1975).

Usage

data(phosphor)

Format

A data frame with 18 observations on the following 3 variables.

inorg

Inorganic soil Phosphorus

organic

Organic soil Phosphorus

plant

Plant Phosphorus content

Source

P. J. Rousseeuw and A. M. Leroy (1987) Robust Regression and Outlier Detection. Wiley, p.156, table 24.

Examples

data(phosphor)
plot(phosphor)
summary(lm.phosphor <- lm(plant ~ ., data = phosphor))
summary(lts.phosphor <- ltsReg(plant ~ ., data = phosphor))

phosphor.x <- data.matrix(phosphor[, 1:2])
cPh <- covMcd(phosphor.x)
plot(cPh, "dd")