Question

What is the function to set column names for a matrix?

(a) names()

(b) colnames()

(c) col.names()

(d) column name cannot be set for a matrix

This question was posed to me in a national level competition.

This intriguing question originated from Overview of R in division History, Overview and Getting Started of R Programming

Answer 1

The correct option is (b) colnames()

The explanation: colnames() is the function to set column names for a matrix. rownames() is the function to set row names for a matrix. But we can’t use both at a time. Column names and row names can be set separately using the colnames() and rownames() functions.