Notes from the Tutorial "Meet The R Dataframe: Examples of Manipulating Data In R":
Use the ChickWeight dataset for this example
data("ChickWeight")
> head (ChickWeight)
weight Time Chick Diet
1 42 0 1 1
2 51 2 1 1
3 59 4 1 1
Selecting A Subset of a R Data Frame
1. using the function subset
> subset(ChickWeight, Diet==4)
2. with a conditional indexing
> ChickWeight[ChickWeight$Diet==4,]
3. using the function which
> ChickWeight[which((ChickWeight$Diet == 4) & (ChickWeight$Time==21)), names(ChickWeight) %in% c("weight","Time")]
