cum3 {boot} | R Documentation |
Calculates an estimate of the third cumulant, or skewness, of a vector. Also, if more than one vector is specified, a product-moment of order 3 is estimated.
cum3(a, b=a, c=a, unbiased=TRUE)
a |
A vector of observations. |
b |
Another vector of observations, if not supplied it is set to the value of a .
If supplied then it must be the same length as a .
|
c |
Another vector of observations, if not supplied it is set to the value of a .
If supplied then it must be the same length as a .
|
unbiased |
A logical value indicating whether the unbiased estimator should be used. |
The unbiased estimator uses a multiplier of n/((n-1)*(n-2))
where n
is
the sample size, if unbiased
is FALSE
then a multiplier of 1/n
is used.
This is multiplied by sum((a-mean(a))*(b-mean(b))*(c-mean(c)))
to give the
required estimate.
The required estimate.