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Introduction screen CumFreq program.
The CumFreq program calcuates the cumulative (nonexceedance) frequency distribution and fits it to a probability distribution. It uses, amongts other, the normal, logistc, exponential and Gumbel distributions. For distribution fitting, the software app linearizes the probability distribution.For a list of linearizations, based on logarithmic and other transformations, see: transformations 
Input tabsheet
The input tabsheet shows the probability distributions that are being used to fit the data to. One can select "best of all" or indicate a preference. The number of intervals needed to prepare the histogram can be entered. 
Cumulative distribution fitting
Distribution fitting is based on plotting positions (the observed data). A 90% confidence interval of the fitted distribution is shown. It is a specialty of CumFreq to employ "generalized" distributions, which makes them fit better than the standard ones. 
Histogram of fitted distribution
The histogram provides the observed and calculated frequencies by interval. The histogram gives an impression of the symmetry of the distribution and whether is skew to the left or to the right. 