R: Finds subsets of a dataframe which is split by variables in a...

subsetBy {doBy} | R Documentation

## Finds subsets of a dataframe which is split by variables in a formula.

### Description

A data frame is split by a formula into groups. Then subsets are found within each group, and the result is collected into a data frame.

### Usage

    subsetBy(formula, subset, data = parent.frame(), select, drop=FALSE,
    join=TRUE, ... )

### Arguments

`formula` | A formula to split by
`subset` | logical expression indicating elements or rows to keep: missing values are taken as false.
`data` | A data frame
`select` | expression, indicating columns to select from a data frame.
`drop` | passed on to [ indexing operator.
`join` | If FALSE the result is a list of data frames (as defined by 'formula'); if TRUE one data frame is returned.
`...` | further arguments to be passed to or from other methods.

### Value

A data frame.

### Author(s)

Søren Højsgaard, sorenh@math.aau.dk

### See Also

See Also `splitBy`

### Examples

    data(dietox)
    subsetBy(~Evit, Weight < mean(Weight), data=dietox)

[Package doBy version 4.5-15 Index]