Learn how to plot coordinates and create straight line graphs to show the relationship between two variables. Also, plot graphs that contain a negative coefficient of x.

This post recommends using Trellis plots instead of 3D bar charts for three-dimensional (three variable) data. In Winner of the Bad Graph Contest Announced, I promised to present alternatives to ...

The iPad renders a 3D plot in real time, which you can reposition, resize, and copy into apps like Keynote or Pages. The entire feature runs locally on the iPad, with no internet connection required.