O'Reilly logo

R Data Analysis Cookbook - Second Edition by Kuntal Ganguly

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

Adding a new column using transform or mutate

Suppose you want to add a new column to reflect each auto's deviation from the mean mpg of the cylinder group to which it belongs:

> auto <- ddply(auto, .(cylinders), transform, mpg.deviation = round(mpg - mean(mpg),2)) > auto <- ddply(auto, .(cylinders), mutate, mpg.deviation = round(mpg - mean(mpg),2)) 

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required