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]