toxicity: Toxicity of Carboxylic Acids Data

Description Usage Format Source References Examples

Description

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

Usage

1

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., Núñez, 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

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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))

Example output

    toxicity           logKow             pKa              ELUMO      
 Min.   :-0.9400   Min.   :-0.5900   Min.   :-0.2000   Min.   :1.860  
 1st Qu.:-0.4675   1st Qu.: 0.7375   1st Qu.: 0.2472   1st Qu.:4.393  
 Median :-0.2250   Median : 1.5750   Median : 0.8913   Median :4.700  
 Mean   :-0.1558   Mean   : 1.6668   Mean   : 0.6489   Mean   :4.344  
 3rd Qu.: 0.0800   3rd Qu.: 2.6475   3rd Qu.: 0.9675   3rd Qu.:4.830  
 Max.   : 0.9000   Max.   : 4.4200   Max.   : 1.0200   Max.   :4.970  
     Ecarb            Emet               RM              IR       
 Min.   :15.40   Min.   :-0.8056   Min.   :15.33   Min.   :1.397  
 1st Qu.:16.89   1st Qu.: 0.8425   1st Qu.:26.56   1st Qu.:1.425  
 Median :17.23   Median : 2.5304   Median :31.43   Median :1.444  
 Mean   :17.19   Mean   : 3.1191   Mean   :34.27   Mean   :1.446  
 3rd Qu.:17.71   3rd Qu.: 4.5039   3rd Qu.:40.72   3rd Qu.:1.470  
 Max.   :18.48   Max.   :11.2898   Max.   :70.03   Max.   :1.478  
       Ts              P         
 Min.   :30.20   Min.   : 1.422  
 1st Qu.:32.55   1st Qu.: 1.462  
 Median :33.15   Median : 1.476  
 Mean   :38.14   Mean   : 6.808  
 3rd Qu.:41.50   3rd Qu.:12.430  
 Max.   :70.50   Max.   :21.630  
   toxicity      logKow         pKa       ELUMO       Ecarb        Emet 
 0.40414939  1.45493782  0.12649876  0.24248964  0.70645314  2.62191920 
         RM          IR          Ts           P 
12.40738642  0.02424896  2.62697107  0.06668465 
       1     2     3     4     5     6     7     8     9
2   0.91                                                
3  -0.32 -0.17                                          
4  -0.25 -0.05  0.64                                    
5  -0.01  0.28  0.48  0.48                              
6   0.88  0.72 -0.50 -0.54 -0.08                        
7   0.78  0.78 -0.11 -0.06  0.36  0.77                  
8   0.32  0.13 -0.57 -0.84 -0.22  0.70  0.41            
9  -0.28 -0.35 -0.11 -0.50  0.00  0.11  0.14  0.72      
10  0.36  0.18 -0.25 -0.07 -0.06  0.41  0.43  0.24  0.09

robustbase documentation built on Nov. 17, 2017, 6:46 a.m.