Basic for() loop in R

Question

I\'m new to loops and R in general. Using the \"iris\" datasets I need to use a for() loop and create an object called \'X.IQR\' that contains the interquartile range of each o

Answer 1

When selecting a subset of the data if you intend to have all the rows, as you have, you can just omit the row selection:

iris[1:150,1:4]

becomes

iris[ ,1:4]

as Richard mentioned in a comment, you can use sapply:

X.IQR = sapply(X = iris[,1:4], FUN = IQR)

sapply will apply the FUN (function) IQR to each element of the iris dataset, which corresponds to its columns.

or using apply:

X.IQR = apply(X = iris[ ,1:4], 2, FUN = IQR)

apply can do the same thing, but its a bit more code and won't always be as clean.

Read more with the excellent response here: R Grouping functions: sapply vs. lapply vs. apply. vs. tapply vs. by vs. aggregate