Examples of non-parametric Discriminant Analysis for one variable (total “excess” photospheric energy, see Leka & Barnes, 2003a) and two variables (same, plus the standard deviation of the horizontal gradients of the horizontal component of the magnetic field, ibid.) for the C1.0+, 24 h event definition. For both, event/non-event NPDA estimates are shown in red/black respectively, and the 50% probability threshold is shown in blue.