This is a small tutorial on how to estimate prices of houses in Pharo using linear regression model from PolyMath. We will then visualize the data points together with the regression line using the new charting capabilities of Roassal3. The main purpose of this blog post is to demonstrate the new charting functionality of Roassal3 that were introduced yesterday. The visualization that we will build is not very pretty, but it will give you a taste of the amazing things that we will be able to do in the near future. Pharo is a pure object-oriented programming language and a powerful environment, focused on simplicity and immediate feedback (think IDE and OS rolled into one).