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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_ptrms_angle(ptrms_best_fit_vector, B_lab_vector):
 """ gives angle between principal direction of the ptrm data and the b_lab vector. this is NOT in SPD, but taken from Ron Shaar's old thellier_gui.py code. see PmagPy on github """

    ptrms_angle = math.degrees(math.acos(old_div(numpy.dot(ptrms_best_fit_vector,B_lab_vector),(numpy.sqrt(sum(ptrms_best_fit_vector**2)) * numpy.sqrt(sum(B_lab_vector**2))))))  # from old thellier_gui.py code  
    return ptrms_angle