Makes a smooth map of point density in 2D. Two columns of x/y coordinates in a rectangular domain are expected. The user can specify the size of the grid (number of rows and columns). The “Radius” value sets the scale r of the kernel. There is currently no automatic selection of “optimal” radius, so this value must be set by the user depending on the scale of interest.
The density estimate is based on one of four kernel functions, with radius parameter r: Gaussian, parabolic, triangular, uniform. For equations, see the Past manual.
The scaling gives an estimate of the number of points per area, not a probability density. The gaussian and paraboloid (quadratic) kernels usually perform best. The uniform kernel gives very low smoothness.