Example of two dimensional visualization for the vaex-viz package. Top left: two dimensional histogram, colour coded by a colour map visualizing the counts in each bin. Top right: similar to the left, but showing the standard deviation in each bin. Middle left: a zoom-in of the E versus L_z space, where a rectangular region is selected using vaex’ selection mechanism. The underlying visualization of all the data is slightly faded out to highlight the selection. Middle right: similar to the top left, but displaying the both the full dataset and the selection, where the selected rectangular region corresponds to a satellite that is not fully phase mixed. Bottom left: similar as the middle right plot but overlaying the mean velocity of the selection using vectors. Bottom right: similar as the bottom left, except now overlaying the velocity dispersion tensor represented by ellipses.