qualityTools (version 1.53)

rsmDesign: Generate a response surface design (i.e. central composite design)

Description

Generates a response surface design containing a cube, centerCube, star and centerStar portion.

Usage

rsmDesign(k = 3, p = 0, alpha = "rotatable", blocks = 1, cc = 1, cs = 1,  
          fp = 1, sp = 1, faceCentered = FALSE)

Arguments

k

integer value giving the number of factors. By default k has the value 3.

p

integer value giving the number of additional factors in the response surface design by aliasing effects. By default p has the value 0.

alpha

character string - alpha shoud be rotatable (default), orthogonal or both. If both values for cc and cs will be DISCARDED.

blocks

integer value giving the number of blocks in the response surface design. By default blocks has the value 1.

cc

integer value giving the number of centerpoints (per block) in the cube portion (i.e. the factorial 2^k design) of the response surface design. Replications of centerpoints in the cube portion can be set with this.By default cc has the value

cs

integer value giving the number of centerpoints in the star portion (alpha) of the response surface design. Replications of centerpoints in the star portion can be set with this. By default cs has the value 1.

fp

integer value giving the number of replications per factorial point (i.e. corner points e.g. (-1,1)). By default fp has the value 1.

sp

integer value giving the number of replications per star point (i.e. alpha). By default sp has the value 1.

faceCentered

logical value wheter to use a faceCentered response surface design or not (i.e. alpha = 1). By default faceCentered has the value FALSE.

Value

• rsmDesign returns an object of class facDesign.

Details

Generated designs consist of a cube, centerCube, star and a centerStar portion. The replication structure can be set with the parameters cc (centerCube), cs (centerStar), fp (factorialPoints) and sp (starPoints).

See Also

facDesign fracDesign fracChoose rsmChoose http://www.r-qualitytools.org/Improve.html

Examples

#central composite design for 2 factors with 2 blocks, alpha = 1.41, 
#5 centerpoints in the cube portion and 3 centerpoints in the star portion:
rsmDesign(k = 2, blocks = 2, alpha = sqrt(2),cc = 5, cs = 3)

#central composite design with both, orthogonality and near rotatability 
rsmDesign(k = 2, blocks = 2, alpha = "both")

#central composite design with
#2 centerpoints in the factorial portion of the design i.e 2
#1 centerpoint int the star portion of the design i.e. 1
#2 replications per factorial point i.e. 2^3*2 = 16
#3 replications per star points 3*2*3 = 18
#makes a total of 37 factor combinations
rsdo = rsmDesign(k = 3, blocks = 1, alpha = 2, cc = 2, cs = 1, fp = 2, sp = 3)
nrow(rsdo) #37