Efficient Effect Size Computation

Description

This packages contains functions to compute effect sizes both based on means difference (Cohen's d and Hedges g), dominance matrices (Cliff's Delta) and stochastic superiority (Vargha-Delaney A).

The computation (especially for Cliff's Delta) is carried on with higly efficient algorithms.

Details

The main functions are:

cliff.delta.

cohen.d.

VD.A.

Change history

0.3.1

Fixed a bug in cohen.d when PAIRED=TRUE, now the PAIRED parameter has no effect, it is left just for compatibility. In a future code clean-up it may be removed

0.4

Implemented a new algorithm with improved memory and time complexity. In particular new time complexity is T = O(n1*log(n2)) vs. the previous T = O(n1*n2), and new memory complexity M = O( n1 + n2 ) vs. the previous M = O( n1 * n2). In practice now the computation becomes feasible in a "reasonable" time.

0.4.1

Code clean-up and optimization using vectorized binary partioning.

0.5

Added Vargha and Delaney A and fixed minor bugs with Cohen.d.

0.5.1

Modified the Vargha and Delaney A computation to minimize accuracy errors.

0.5.2

Fixed bug in cliff.delta.

0.5.3

Fixed bug in cohen.d.formula.

0.5.4

Fixed minor issue detected by check.

0.5.5

Changed the effsize field magnitude to a factor value.

0.6.0

Implemented paired computation and CI computation with non-central t-distributions for cohen.d.

0.6.1

Added ability to specify factor vector and data vector for 'cliff.delta' function (thanks to Joses W. Ho).

Author(s)

Marco Torchiano http://softeng.polito.it/torchiano/