There is four ways that effects can be defined in GRD. "factor = slope(s)" will vary the means by an amount of s for each step of the factor; "factor = extent(s)" will vary the means uniformly so that there is a difference of s between the first and the last factor level; "factor = custom(a,b,c..)" will alter each means by an amount of a for the first, b for the second, etc. Finally "factor = Rexpression("R code")" will apply R code to all levels of the factors. R code result alters the base mean.

slope(s)

extent(s)

custom(...)

Rexpression(str)

## Arguments

s the size of the effect a sequence with the sizes of the effects R code string

## Value

These internal functions are not meant to be used in isolation in any meaningful way...