Robotics toolbox 'r' parameter in 'Link' class

Hello,

In the robotic toolbox, I am having some issues understanding what the 'r' parameter refers to in the 'link' class. The comment next to the 'r' parameter says that r is the 'link COG wrt link coordinate frame 3x1' . Does r refer to the location of the centre of mass with respect to the ith joint frame? By link coordinate, does it mean the ith joint frame coordinate?

Thank you

[Cam Salzberger]

This is referring to the Link class from Peter Corke's Robotics Toolbox, not the MathWorks Robotics System Toolbox. Just to be clear.