dCohensd
The distribution of Cohen's d
These functions use some conversion to and from the t distribution to provide the Cohen's d distribution. There are four versions that act similar to the standard distribution functions (e.g. the d.
, p.
, q.
, and r.
functions), and three convenience functions.
 Keywords
 univar
Usage
dd(x, df, populationD = 0)
pd(q, df, populationD = 0, lower.tail = TRUE)
qd(p, df, populationD = 0, lower.tail = TRUE)
rd(n, df, populationD = 0)
dCohensd(x, df, populationD = 0)
pCohensd(q, df, populationD = 0, lower.tail = TRUE)
qCohensd(p, df, populationD = 0, lower.tail = TRUE)
rCohensd(n, df, populationD = 0)
pdExtreme(d, n, populationD=0)
pdMild(d, n, populationD=0)
pdInterval(ds, n, populationD=0)
cohensdCI(d, n, conf.level = .95)
Arguments
 x, q, d
 Vector of quantiles, or, in other words, the value(s) of Cohen's d.
 ds
 A vector with two Cohen's d values.
 p
 Vector of probabilites (pvalues).
 df
 Degrees of freedom.
 n

Desired number of Cohen's d values for
rCohensd
andrd
, and the number of participants/datapoints forpdExtreme
,pdMild
, andpdInterval
.  populationD
 The value of Cohen's d in the population; this determines the center of the Cohen's d distribution. I suppose this is the noncentrality parameter.
 lower.tail
 logical; if TRUE (default), probabilities are the likelihood of finding a Cohen's d smaller than the specified value; otherwise, the likelihood of finding a Cohen's d larger than the specified value.
 conf.level
 The level of confidence of the confidence interval.
Details
The functions use convert.d.to.t
and convert.t.to.d
to provide the Cohen's d distribution.
Value
dCohensd
(or dd
) gives the density, pCohensd
(or pd
) gives the distribution function, qCohensd
(or qd
) gives the quantile function, and rCohensd
(or rd
) generates random deviates.pdExtreme
returns the probability (or probabilities) of finding a Cohen's d equal to or more extreme than the specified value(s).pdMild
returns the probability (or probabilities) of finding a Cohen's d equal to or less extreme than the specified value(s).pdInterval
returns the probability of finding a Cohen's d that lies in between the two specified values of Cohen's d.
See Also
convert.d.to.t
, convert.t.to.d
, dt
, pt
, qt
, rt
Examples
### Generate 10 random Cohen's d values
rCohensd(10, 20, populationD = .5);
### Probability of findings a Cohen's d smaller than
### .5 if it's 0 in the population (i.e. under the
### null hypothesis)
pCohensd(.5, 64);
### Probability of findings a Cohen's d larger than
### .5 if it's 0 in the population (i.e. under the
### null hypothesis)
1  pCohensd(.5, 64);
### Probability of findings a Cohen's d more extreme
### than .5 if it's 0 in the population (i.e. under
### the null hypothesis)
pdExtreme(.5, 64);
### Probability of findings a Cohen's d more extreme
### than .5 if it's 0.2 in the population.
pdExtreme(.5, 64, populationD = .2);
Community examples
Looks like there are no examples yet.