[R] mathematical expression in varnames of lattice parallel plot

[Doris Brockmann]

How can I insert mathematical expressions for variable names in a 
lattice parallel plot? I tried to implement mathematical expressions in 
varnames, however, without success.

For example, neither

parallel(~iris[1:4] | Species, iris,

         varnames=c("P[Width]", "Petal[length]", "alpha[Width]", "Sepal[Length]"))

nor

parallel(~iris[1:4] | Species, iris,
         varnames=c(expression(P[Width]), expression(Petal[length]), expression(alpha[Width]),
			expression(Sepal[Length])))

result in the desired labeling of the different axes of the parallel plot.

Thank you very much.

Regards,

Doris

-- 
---------------------------------------------------------------------------
Dr.-Ing. Doris Brockmann
Post-doctoral researcher
INRA - Laboratoire de Biotechnologie de l'Environnement (LBE)
Avenue des Etangs,
Narbonne, F-11100, France
Tel : (33)(0)4 68 42 51 88 (standard : 51 51)
Fax : (33)(0)4 68 42 51 60
email: brockman at supagro.inra.fr
http://www.montpellier.inra.fr/narbonne