toxicity {robustbase}R Documentation

Toxicity of Carboxylic Acids Data

Description

The aim of the experiment was to predict the toxicity of carboxylic acids on the basis of several molecular descriptors.

Usage

data(toxicity)

Format

A data frame with 38 observations on the following 10 variables which are attributes for carboxylic acids:

toxicity
aquatic toxicity, defined as log(IGC50^(-1)); typically the “response”.
logKow
log Kow, the partition coefficient
pKa
pKa: the dissociation constant
ELUMO
Energy of the lowest unoccupied molecular orbital
Ecarb
Electrotopological state of the carboxylic group
Emet
Electrotopological state of the methyl group
RM
Molar refractivity
IR
Refraction index
Ts
Surface tension
P
Polarizability

Source

The website accompanying the MMY-book: http://www.wiley.com/legacy/wileychi/robust_statistics

References

Maguna, F.P., N'u~nez, M.B., Okulik, N.B. and Castro, E.A. (2003) Improved QSAR analysis of the toxicity of aliphatic carboxylic acids; Russian Journal of General Chemistry 73, 1792–1798.

Examples

data(toxicity)
summary(toxicity)
plot(toxicity)
plot(toxicity ~ pKa, data = toxicity)

## robustly scale the data (to scale 1) using Qn
(scQ.tox <- sapply(toxicity, Qn))
scTox <- scale(toxicity, center = FALSE, scale = scQ.tox)
csT <- covOGK(scTox, n.iter = 2,
              sigmamu = s_Qn, weight.fn = hard.rejection)
as.dist(round(cov2cor(csT$cov), 2))

[Package robustbase version 0.4-3 Index]