condroz R Documentation

## Condroz Data

### Description

Dataset with pH-value and Calcium content in soil samples, collected in different communities of the Condroz region in Belgium. The data pertain to a subset of 428 samples with a pH-value between 7.0 and 7.5.

### Usage

data(condroz, package="robustbase")

### Format

A data frame with 428 observations on the following 2 variables.

Ca

Calcium content of the soil sample

pH

pH value of the soil sample

### Source

Hubert and Vandervieren (2006), p. 10. This dataset is also studied in Vandewalle et al. (2004).

### References

See also those for adjbox.

Goegebeur, Y., Planchon, V., Beirlant, J., Oger, R. (2005). Quality Assesment of Pedochemical Data Using Extreme Value Methodology, Journal of Applied Science, 5, p. 1092-1102.

Vandewalle, B., Beirlant, J., Hubert, M. (2004). A robust estimator of the tail index based on an exponential regression model, in Hubert, M., Pison G., Struyf, A. and S. Van Aelst, ed., Theory and Applications of Recent Robust Methods, Birkhäuser, Basel, p. 367-376.

### Examples

  adjbox(condroz\$Ca)