computeCohen_d(x1, x2, varargin)

call: d = computeCohen_d(x1, x2, varargin)

EFFECT SIZE of the difference between the two
means of two samples, x1 and x2 (that are vectors),
computed as "Cohen's d".

If x1 and x2 can be either two independent or paired
samples, and should be treated accordingly:

d = computeCohen_d(x1, x2, 'independent'); [default]
d = computeCohen_d(x1, x2, 'paired');

Note: according to Cohen and Sawilowsky:

d = 0.01 --> very small effect size
d = 0.20 --> small effect size
d = 0.50 --> medium effect size
d = 0.80 --> large effect size
d = 1.20 --> very large effect size
d = 2.00 --> huge effect size