• randomize(A)—Randomizes the runs by permuting the rows within each block of the design matrix A in a random manner.
• doelabel(A, Vals)—Replaces the labeling and the coding of the design matrix A with the labels and values recorded in the matrix Vals.
This function applies only to coded designs.
• block(A, b/“blockgen”)—Returns the design matrix A with b blocks using default blocking generators. To specify the block generators directly, use "blockgen" instead of b. Blocking lowers the resolution of the design matrix at least by one order. The algorithm used for generating the blocking is described in Statistics For Experimenters by Box, Hunter, and Hunter.
This function applies only to 2–level factorial (full or fractional) designs that are unblocked and in their coded form (+1/-1).
• foldover(A, [“foldfac”])—Returns a 2-block design matrix with twice the number of runs as the design matrix A. For the additional runs, all the levels are reversed unless “foldfac” is specified, in which case only the levels of the factors named in that string are reversed. The foldover function increases the resolution of fractional factorial design matrices so the alias structure of the factorial is modified accordingly.
This function applies only to 2–level fractional factorial designs that are unblocked and in their coded form (+1/-1).
Arguments
• A is a design matrix.
• Vals is a matrix with factor labels in its first column and with the real values of each level in the remaining columns:
[“label”, lowest level, ..., highest level]
When the factors do not all have the same number of levels, shorter rows are padded with NaNs:
• b is an integer specifying the number of required blocks. rows(A) ≥ b ≥ 1
• “blockgen” is a string specifying the block generators, such as “AB, CD”. The number of blocks is 2n where n is the number of generators specified in “blockgen”. For example, “AB, CD” generates four blocks. For the separators, you can use a space, a comma, a colon, or a semicolon.
• “foldfac” (optional) is a string specifying the factors to fold over, such as “A, B, C”. For the separators, you can use a space, a comma, a colon, or a semicolon.
