salinity {rrcov}R Documentation

Salinity Data

Description

This is a data set consisting of measurements of water salinity (i.e., its salt concentration) and river discharge taken in North Carolina's Pamlico Sound; This dataset was listed by Ruppert and Carroll (1980). In Carrol and Ruppert (1985) the physical background of the data is described. They indicated that observations 5 and 16 correspond to periods of very heavy discharge and showed that the discrepant observation 5 was masked by observations 3 and 16 i.e. only after deletion of these observations it was possible to identify the influential observation 5.

This data set is a prime example of the masking effect.

Usage

data(salinity)

Format

A data frame with 28 observations on the following 4 variables.

X1
Lagged Salinity
X2
Trend
X3
Discharge
Y
Salinity

For convenience, the data sets salinity.x, a matrix with the three (independent) variables of the data frame, and salinity.y, the numeric vector giving the fourth (dependent) variable, are provided as well.

Source

P. J. Rousseeuw and A. M. Leroy (1987) Robust Regression and Outlier Detection. Wiley, p.82, table 5.

Examples

data(salinity)
covMcd(salinity.x)

summary(lm.salinity <- lm(salinity.y ~ salinity.x))


[Package rrcov version 0.2-5 Index]