v0.0.5

Introduce special functions: logit and sigmoidal logistic functions

v0.0.4

1. Descriptive statistics: population variance, population covariance and population standard deviation
2. Order statistics: quantile and percentile
3. Breaking change: :error is replaced with nil for invalid cases

v0.0.3

1. Statistics: variance, covariance and standard deviation
2. Distance: weighted Pearson's

v0.0.2

First initial release

1. Distance metrics: Pearson's, Minkowski, Euclidean and Manhattan
2. Correlation: Pearson's
3. Descriptive statistics: mean, median, mode and range
4. General: calculate nth root