```
pickSizeTolerance(x, metric, tol = 1.5, maximize)
pickSizeBest(x, metric, maximize)
```pickVars(y, size)

caretFuncs
lmFuncs
rfFuncs
treebagFuncs
ldaFuncs
nbFuncs

x

a matrix or data frame with the performance metric of interest

metric

a character string with the name of the performance metric that
should be used to choose the appropriate number of variables

maximize

a logical; should the metric be maximized?

tol

a scalar to denote the acceptable difference in optimal performance
(see Details below)

y

a list of data frames with variables

`Overall`

and `var`

size

an integer for the number of variables to retain

`functions`

argument of `rfeControl`

. See `rfeControl`

for details on how these functions should be defined.

`rfeControl`

, `rfe`