# Compute slip vector
    if (active_cells0 > thresh_active_cells_translation and active_cells1 > thresh_active_cells_translation):
        slipvector = NCC.normalized_cross_correlation(frame0, frame1)
        slipvectors_delta = np.vstack((slipvectors_delta, slipvector))
        slipvectors = np.vstack((slipvectors, slipvectors[-1]+slipvector))
        
        slipvector_ncc_1 = NCC.normalized_cross_correlation2(frame0, frame1)
        slipvectors_ncc_1_delta = np.vstack((slipvectors_ncc_1_delta, slipvector_ncc_1))
        slipvectors_ncc_1 = np.vstack((slipvectors_ncc_1, slipvectors_ncc_1[-1]+slipvector_ncc_1))
        
        slipvector_ncc_2 = NCC.normalized_cross_correlation3(frame0, frame1)
        slipvectors_ncc_2_delta = np.vstack((slipvectors_ncc_2_delta, slipvector_ncc_2))
        slipvectors_ncc_2 = np.vstack((slipvectors_ncc_2, slipvectors_ncc_2[-1]+slipvector_ncc_2))

        slipvector_pc = NCC.normalized_cross_correlation4(frame0, frame1)
        slipvectors_pc_delta = np.vstack((slipvectors_pc_delta, slipvector_pc))
        slipvectors_pc = np.vstack((slipvectors_pc, slipvectors_pc[-1]+slipvector_pc))
     
        frame0 = frame1
        active_cells0 = active_cells1
    else:
        slipvectors_delta = np.vstack((slipvectors_delta, np.zeros(2)))
        slipvectors = np.vstack((slipvectors, slipvectors[-1]))
        
        slipvectors_ncc_1_delta = np.vstack((slipvectors_ncc_1_delta, np.zeros(2)))
        slipvectors_ncc_1 = np.vstack((slipvectors_ncc_1, slipvectors_ncc_1[-1]))
        
        slipvectors_ncc_2_delta = np.vstack((slipvectors_ncc_2_delta, np.zeros(2)))
        slipvectors_ncc_2 = np.vstack((slipvectors_ncc_2, slipvectors_ncc_2[-1]))