Examples of density maps created from big datasets. Left: drop-off locations of the Yellow cab taxies in New York City between 2009 and 2015. In total ∼1 billion GPS coordinates are plotted. Middle: density plot of particle position from the Aquarius pure dark matter simulations (Springel et al. 2008, Aquarius A level 2), ∼0.6 billion particles. Right: open street map GPS data, showing ∼2 billion coordinates.