expression {m61r}

Formula to be run on a data.frame given a group

Description

Evaluate a formula on the data.frame.

Usage

expression_(df, group=NULL, fun_expr)

Arguments

df

data.frame

group

formula that describes the group

fun_expr

formula that describes the expression to be run on the data.frame

Value

The function returns a list. Each element of the list get the result of processed expressions determined in ... on the whole data frame df if group is kept NULL, or for each group determined in group otherwise. The class of each element is intrinsic to the output of the expression determined in argument ....

Examples

expression_(CO2,fun_expr=~mean(conc))

expression_(CO2,fun_expr=~conc/uptake)

# with group
expression_(CO2,group=~Type,fun_expr=~mean(uptake))

expression_(CO2,group=~Type,fun_expr=~lm(uptake~conc))