What is "cumfreq"

In statistics and data analysis the application software CumFreq is a free and user-friendly tool for cumulative frequency analysis of a single variable and for probability distribution fitting.

Originally the method was developed for the analysis of hydrological measurements of spatially varying magnitudes (e.g. hydraulic conductivity of the soil) and of magnitudes varying in time (e.g. rainfall, river discharge) to find their return periods. However, it can be used for many other types of phenomena, including those that contain negative values.