You are looking at historical revision 20485 of this page. It may differ significantly from its current revision.

Still under testing!


This library is a port of Larry Hunter's Lisp statistics library to chicken scheme.

The library provides a number of formulae and methods taken from the book "Fundamentals of Biostatistics" by Bernard Rosner (5th edition).

Provided Functions


(random-pick items)
given a list of items, returns a random item.
(random-sample n items)
given a number of items to select, n, and a list of items to select from, items, returns a random sample without replacement of size n.
(sign n)
given a number n, returns 0, 1 or -1 according to if n is zero, positive or negative.
(square n)
given a number n, returns the square of n.

Descriptive statistics

(mean items)
given a list of numbers, items, returns the arithmetic mean of the items (the sum of the numbers divided by the number of numbers).
(median items)
given a list of numbers, items, returns the value which separates the upper and lower halves of the list of numbers.
(mode items)
(geometric-mean items)
given a list of numbers, items, returns the geometric mean of the items (the result of multiplying the items together and then taking the nth root, where n is the number of items).
(range )
(percentile items n)
(variance items)
(standard-deviation items)
(coefficient-of-variation items)
(standard-error-of-the-mean )
(mean-sd-n items)

Distributional functions

Confidence intervals

Hypothesis testing


(non parametric)

Sample size estimates

Correlation and regression

Significance test functions


Peter Lane wrote the scheme version of this library. The original Lisp version was written by Larry Hunter.


GPL version 3.0.


Needs srfi-1, srfi-25, srfi-69, vector-lib, numbers, extras, foreign, format

Uses the GNU scientific library for basic numeric processing, so requires libgsl, libgslcblas and the development files for libgsl.

Version History

trunk, for testing