Algorithm (Workflow)

This function, PLtransR, is designed to rotate a list of 2D points using a given rotation matrix. Below is a detailed explanation of the algorithm and its parameters.

Input Parameters

• PL: A point list represented as an n x 2 matrix, where each row corresponds to a point in 2D space.
• R: A 2 x 2 rotation matrix. If R is a scalar, it is assumed to be an angle in radians, and the function rot(R) is called to convert it into a rotation matrix.

Output

• PL: The transformed point list after applying the rotation.

Algorithm Steps

1. Check if R is a scalar. If true, convert it to a rotation matrix using the rot function.
2. Apply the rotation to the point list PL by multiplying the rotation matrix R with the transpose of PL, and then transpose the result back.
3. If no output is requested (i.e., nargout == 0), plot the transformed points using SGfigure and PLplot.

Example Usage

To rotate a square, you can use the following example:

PL = PLcircle(10, 4); 
CPLplot([PL; NaN NaN; PLtransR(PL, rot(pi/6))]);

This example creates a circle of points and then rotates it by pi/6 radians.