This online calculator computes text "fitness". That is, how similar the given text to other texts written in English language.

This online calculator takes a list of events along with number of times the particular event occurred and calculates the probability (and log probability) of each event by dividing event count to the total number of events.

This online calculator calculates measure known as fitness score, of how given text is similar to a typical English text. It uses frequencies of unigrams, bigrams and trigrams to calculate fitness score. The reference frequencies are calculated from Leipzig Corpora Collection and can be downloaded from http://practicalcryptography.com/cryptanalysis/text-characterisation/quadgrams/. The less value you get, the better.

This online calculator calculates measure known as fitness score, of how given text is similar to a typical English text. It uses logarithms of probabilities with normalization to calculate fitness score. The reference frequencies are calculated from Leipzig Corpora Collection and can be downloaded from http://practicalcryptography.com/cryptanalysis/text-characterisation/quadgrams/. The less value you get, the better.

This online calculator computes covariance between two discrete random variables. It also shows the expected value (mean) of each random variable. You can find the formula used for the calculation of covariance below the calculator.

This online calculator analyzes and summarizes sequence of events on a timeline. It calculates days passed between events, as well as statistical data, e.g. a mean time between events, a variance and a deviation

This online calculator calculates seasonal indices based on quarterly data using the method of simple averages

This online calculator generates a list of Russian surnames based on the frequency of occurrence of first and last names.

This online calculator allows you to use a table of species distrubution in samples to calculate the Schorygin coefficient (or commonality coefficient of specific abundance) in pairs for each pair in a series of samples.

The Jaccard index refers to binary similarity coefficients and is a commonly used measure for analyzing the species composition of communities or samples in biological studies. This similarity measure is the intersection of sets. The calculator is designed primarily for biologists, but is universal for estimating the intersection of sets and can be applied to other, non-biological problems.

This calculator allows you to calculate species dominance using the two indicators most commonly considered in community analyses, species occurrence and abundance.

This calculator constructs a scatter diagram (dot plot) that depicts the relashionship between two variables by putting each pair as point on the Cartesian plane. The values of variables are set as pairs of numbers separated by semicolons or tabs.