Extract Pooled Standard Deviation

DESCRIPTION:

The pooled estimated standard deviation is obtained by adding together the residual sum of squares for each non-null element of object , dividing by the sum of the corresponding residual degrees-of-freedom, and taking the square-root.

USAGE:

pooledSD(object) 

REQUIRED ARGUMENTS:

object
an object inheriting from class lmList.

VALUE:

the pooled standard deviation for the non-null elements of object , with an attribute df with the number of degrees-of-freedom used in the estimation.

SEE ALSO:

,

EXAMPLES:

fm1 <- lmList(Orthodont) 
pooledSD(fm1)