https://en.wikipedia.org/wiki/Mathematical_constant
Cumulative distribution function
https://en.wikipedia.org/wiki/Cumulative_distribution_function
Complementary cumulative distribution function (tail distribution)
cdf (cumulative distribution function)
cdf complement (this is 1 – cdf)
hazard (the event rate at time t conditional on survival until time t or later; useful when modeling failure in mechanical systems)
chf (cumulative hazard function which measures the accumulation of hazard over time)
kurtosis (a measure of the ‘peakedness’ of a probability distribution)
kurtosis_excess (has a distribution fatter tails than a normal distribution?)
mean (the expected value)
median (the value separating the lower and higher halves of a distribution)
mode (the point at which the probability mass or density function takes its maximum)
pdf (probability density function)
range (the length of the smallest interval which contains all the data)
quantile (points taken at regular intervals from the cdf)
skewness (a measure of the asymmetry of a probability distribution)
support (the smallest closed interval/set whose complement has probability zero)
variance (how far do values differ from the mean)
