Gaussian mixture model and data over u and v velocities. Bottom-left panel: data is plotted as a 2D histogram, overlaid by the 1-sigma ellipses of the five Gaussians of the mixture model. The shading of the ellipses correspond to the weight of the respective Gaussians, where a darker colour correspond to a larger weight. Top and bottom-right panels: fitted model and the data are marginalised to 1D histograms over u and v.