Pendulum dynamic response using MATLAB

The ball's resting point defines the reference for the angle (zero degrees). In x-y coordinates, we have a zero angle along the bottom part of the vertical line. A positive angle is when the ball moves counter clockwise from the resting point. A negative angle is when the ball moves clockwise from the resting point.
The parameters of the pendulum are:
Mass, m=0.1 [kg]
Rod length, l=1 [m] (rod is weightless and rigid)
Friction coefficient, k=0.08 [m Kg]
Gravitational acceleration, g=9.8 m/s