effsize-package: Efficient Effect Size Computation
In effsize: Efficient Effect Size Computation

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.

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).
0.6.2: na.rm in cohen.d removes all incomplete pairs when paired.
0.6.3: fixed bug in cohen.d when na.rm=TRUE, minor changes in the documentation (thanks to P.Thomas)
0.6.4: Fixed a bug related to pairedcohen.d with NAs. Minor documentation changes
0.7.0: Refactored tests using testthat package. Fixed a bug in cliff.delta returning inconsistent results when the dominance matrix is returned. Fixed issue concerning CI. Fixed bug in cohen.d when using noncentral parameter for negative effect sizes.
0.7.1: Fixed minor bugs in cliff.delta and cohen.d
0.7.2: Fixed bugs in cohen.d, order of factors is now observed and CI are computed correctly
0.7.3: Fixed bugs in cohen.d, possible endless loop, cleaned code
0.7.4: Fixed bugs in cliff.delta when values are factors
0.7.5: Fixed bugs in cohen.d for paired data
0.7.6: Fixed bugs in cohen.d for CI of paired data
0.7.7: Fixed bugs in cohen.d for non-pooled SD, plus a few pull requests on documentation
0.7.8: Fixed bug in cohen.d wrong correct type check
0.7.9: Fixed tests to be compatible with upcoming R 4.0, that sets stringsAsFactors to FALSE by default
0.8.0: Added non-central CI estimation for single sample cohen.d, fixed a bug related to order of data and added a subject parameter for paired cohen.d