[SomethingRandom]

I just want to confirm how the OpenFOAM's motion solver calculates the oscillating rotating motion.

Is it something equivalent to this python code?
```
def point_rotate_array(pointx, pointy, rotationAngle, rotateAbout):
pointx = np.array(pointx)
pointy = np.array(pointy)

tempx = pointx - rotateAbout[0]
tempy = pointy - rotateAbout[1]

xPrime = tempx * np.cos(rotationAngle) - tempy * np.sin(rotationAngle)
yPrime = tempy * np.cos(rotationAngle) + tempx * np.sin(rotationAngle)

xPrime = xPrime + rotateAbout[0]
yPrime = yPrime + rotateAbout[1]

amplitude_x = xPrime - pointx
amplitude_y = yPrime - pointy

return [amplitude_x, amplitude_y]
```