Calculates the hypsometric curve for a given DEM.The hypsometric curve is an empirical cumulative distribution function of elevations in a catchment or of a whole planet. The tool calculates both the relative (scaled from 0 to 100 percent) and absolute (minimum to maximum values) distributions. The former scales elevation and area by the maximum values. Such a non-dimensional curve allows one to asses the similarity of watersheds as differences in hypsometric curves arise from different geomorphic processes shaping a landscape.In case the hypsometric curve should not be calculated for the whole elevation range of the input dataset, a user-specified elevation range can be specified with the classification constant area.The output table has two attribute columns with relative height and area values, and two columns with absolute height and area values. In order to plot the non-dimensional hypsometric curve as diagram, use the relative area as x-axis values and the relative height for the y-axis. For a diagram with absolute values, use the absolute area as x-axis values and the absolute height for the y-axis.