This post shows how to use the likert R package. It allows to build 0-centered stacked barplot to study likert type items.
Likert is an R package designed to help analyzing and visualizing Likert type items. It has been developped by Jason Bryer and Kim Speerschneider.
This barplot comes from the demo page and has been sent by Carlos Ortega.
It allows to analyse the reading attitudes from a panel of people. Each line represents a question. The barplot explains the feeling of people concerning this question.