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scidoe_ccdesign

A Central Composite Design of Experiments

Calling Sequence

H = scidoe_ccdesign(nbvar)
H = scidoe_ccdesign(nbvar,"Name1","Parameter1","Name2","Parameter2")

Parameters

nbvar :

a 1-by-1 matrix of doubles, positive integer, the number of variables of the experiment

Name :

a 1-by-n matrix of strings. The options are "type", "alpha" and "center".

Parameter :

a 1-by-n matrix of strings, describing the design.

Description

The function produces a Central Composite Design of experiments. A CCD is composed by a factorial block design, a block of axial (star) points and a matrix of center points (zeros)

The CCD can be specified, as described in "Parameters". The default design is "circumscribed" and "orthogonal".

Circumscribed and Inscribed can be rotatable designs, but Faced cannot. For Faced CCD, alpha =1. If "type" is specified, while "alpha" is not, then default value is "orthogonal". If the design is orthogonal, alpha = sqrt(nbvar*(1+(nao/na))/(1+(nco/nc))), nc the factorial points, nco the center points added to the factorial design, na the axial points, nao the center points added to the axial points. If the design is rotatable, alpha = nc^1/4, where nc=2^nbvar are the factorial points.

The user can specify the number of center points in each block of the design (factorial and axial). If "Parameter" is [2 3], then there are 2 center points in the factorial block and 3 points in the axial points block. Default value is [4 4] (a total of 8 center points in the CCD).

There is no strict order in the input of the above options. scidoe_ccdesign(2,"type","inscribed","center",[2 3]) will output the same as scidoe_ccdesign(2,"center",[2 3],"type","inscribed")

Examples

// Circumscribed orthogonal design
H = scidoe_ccdesign(2)
// Inscribed orthogonal design
H = scidoe_ccdesign(3,"type","inscribed")
// Faced CCD
H = scidoe_ccdesign(2,"type","faced")
// Inscribed rotatable CC Design
H = scidoe_ccdesign(3,"type","inscribed","alpha","rotatable")
// Orthogonal CCD with 2 2 center points in the factorial block and 3 center points in the star points block
H = scidoe_ccdesign(3,"center",[2 3])

Bibliography:
George E. P. Box, J. Stuart Hunter, William G. Hunter, "Statistics for experimenters Design,Innovation and Discovery", Second Edition, 2005
http://en.wikipedia.org/wiki/Central_composite_design
http://rgm2.lab.nig.ac.jp/RGM2/func.php?rd_id=rsm:ccd
http://www.mathworks.com/help/toolbox/stats/f56635.html
http://www.itl.nist.gov/div898/handbook/pri/section3/pri3361.htm

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