second_order_mat: Second Order Model Design Matrix
In toledo60/OACD: Orthogonal Array Composite Designs

Description Usage Arguments Value Examples

Obtain second order design matrix from a specified model. Optionally, be able to extract specific terms from the matrix (i.e linear terms, quadratic terms, or bilinear terms)

1	second_order_mat(model, terms = "full")

`model`	Input a second order model
`terms`	specify if you only want to extract certain terms from the second order design matrix

A design matrix from initial second order model

model2 <- lm(ybar ~ (A+B)^2 + I(A^2)+I(B^2), data= AEL_dat)
second_order_mat(model2)
second_order_mat(model2, terms = "linear")
second_order_mat(model2, terms = "quadratic")