Algorithm (Workflow)

This function, PLofT, is designed to extract a point list from the translation part of a list of homogeneous transformation (HT) matrices. It is part of the SolidGeometry library and was introduced in version 4.5.

Input Parameters

• T0: A list of matrices in 2D or 3D. The function expects these matrices to be homogeneous transformation matrices.

Output Results

• PL: A point list extracted from the translation components of the input matrices.

Algorithm Explanation

The function begins by checking the size of the second dimension of the input matrix list T0:

• If size(T0,2) == 3, it indicates that the matrices are 2D homogeneous transformation matrices. The function extracts the translation components from the third column of each matrix, specifically the first two rows, and stores them in the point list PL.
• If the condition is not met, it assumes the matrices are 3D homogeneous transformation matrices. It extracts the translation components from the fourth column of each matrix, specifically the first three rows, and stores them in the point list PL.

The function uses the squeeze function to remove singleton dimensions from the extracted data, and the transpose operator (') to ensure the point list is in the correct orientation.

Additional Functionality

If the function is called without output arguments (nargout == 0), it performs additional operations:

• It calls SGfigure to create a new figure window.
• It uses tplot to plot the transformation matrices T0.
• It uses PLplot to plot the point list PL with a magenta line of width 2.

This function is useful for visualizing the path described by a series of transformation matrices, particularly in robotics and kinematics applications.