Principal component analysis applied to the mean-subtracted Stokes V profiles. The first three eigenvectors (top row) and their corresponding coefficients (2nd-4th row) are shown. The vertical line in the eigenvector panels indicates the radial velocity offset for AD Leo, of approximately 12.4 km s⁻¹, while the horizontal dotted line in all panels represents the null line. The coefficients are displayed by epoch: 2019a (2nd row), 2019b (3rd row), 2020a (4th row) and 2020b (5th row). They are phase folded using Eq. (1) and colour-coded by rotation cycle.