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Click on any of the above 16 programs for more information and free downloads. 

This data set of crop yield and soil salinity
needs an analysis by a segmented regression
software model to determine the response and
salt tolerance or resistance of the potato crop.
Here, the soil salinity is expressed in terms of electric conductivity (EC) of an extract (e) from a saturated soil paste ==> ECe If the relation shows a not descending line in the first stretch of ECe values, e.g. from ECe=0 to ECe=7, then this is a stretch of "no effect", and the tolerance level can be set at ECe=7 beyond which value the yields start to decline due to negative influence of the saline soil. For more explanation of this application program of the calculator see this lecture note on segmented regression 

This data set of annually maximum 1day rainfalls
needs an analysis by probability distribution
fitting to determine the frequency of occurrence
of extreme values and the cumulative frequency.
Such an analysis can be done with the CumFeq software model, which application program gives a histogram. It also calculates the correlation between predicted and observed values. The applicability of the probability distribution is expressed in terms of goodness of fit. For more explanation see this lecture note on frequency analysis 