#### Kdensity

The smooth kdensity option is a way to plot a kernel density estimate (a smooth histogram) for a random collection of points, using Gaussian kernels. A Gaussian is placed at the location of each point in the first column and the sum of all these Gaussians is plotted as a function. The value in the second column is taken as weight of the Gaussian. To obtain a normalized histogram, this should be 1/number-of-points. By default gnuplot calculates and uses the bandwidth which would be optimal for normally distributed data.

        default_bandwidth = sigma * (4/3N) ** (0.2)

This will usually be a very conservative, i.e. broad bandwidth. Alternatively, you can provide an explicit bandwidth.

        plot $DATA smooth kdensity bandwidth <value> with boxes

The bandwidth used in the previous plot is stored in variable GPVAL_KDENSITY_BANDWIDTH.