Description Usage Arguments Value Note Author(s) References See Also Examples
function to generate simplex lattice and simplex centroid mixture designs with optional center points and axial points.
1 2 
p 
numerical value giving the amount of factors. 
n 
numerical value specifying the degree (ignored if type = “centroid”). 
type 
character string giving the type of design. 
center 
logical value specifying whether (optional) center points will be added. 
axial 
logical value specifying whether (optional) axial points will be added. 
delta 
numerical value giving the delta (see references) for axial runs. No default setting. 
replicates 
vector with the number of replicates for the different design points i.e. c(center = 1, axial = 1, pureBlend = 1, BinaryBlend = 1, p3 blend, p2 blend, p1 blend). 
lower 
vector of lowerbound constraints on the component proportions (i.e. must be given in percent). 
total 
vector with

randomize 
logical value. If ‘TRUE’ the RunOrder of the mixture design will be randomized (default). 
seed 
numerical value giving the input for 
mixDesig()
returns an object of class mixDesign
.
In this version the creation of (augmented) lattice, centroid mixture designs is fully supported. Getters and Setter methods for the mixDesign object exist just as for objects of class facDesign
(i.e. factorial designs).
The creation of constrained component proportions is partially supported but don't rely on it. Visualization (i.e. ternary plots) for some of these designs can be done with the help of the wirePlot3
and contourPlot3
function.
Visualization is however BETA and the analysis of mixture designs is not as convenvient as for objects of class facDesign
(i.e. needs to be done manually, at this point). Feedback is welcome...
For an example in context which shows the usage of the function mixDesign()
to an object of class facDesign
,
please read the vignette for the package qualityTools
at http://www.rqualitytools.org/html/Improve.html.
Thomas Roth [email protected]
CORNELL: Experiments with Mixtures  3rd Ed. New Jersey: Wiley, 2011.
CHASALOW, S. ; BRAND, R.: Generation of Simplex Lattice Points. Journal of the Royal Statistical Society. Series C (Applied Statistics), Vol. 44, No. 4 (1995), pp. 534545.
facDesign
fracDesign
rsmDesign
wirePlot3
contourPlot3
http://www.rqualitytools.org/html/Improve.html
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43  #simplex lattice design with center (default response added with NA's)
mixDesign(p = 3, n = 2, center = FALSE)
#simplex lattice design with a center (default response added with NA's)
mixDesign(p = 3, n = 2, center = TRUE)
#simplex lattice design with augmented points (default response added with NA's)
mixDesign(p = 3, n = 2, center = FALSE, axial = TRUE)
#simplex lattice design with augmented points, center and 2 replications
#(default response added with NA's)
mixDesign(p = 3, n = 2, center = TRUE, axial = TRUE, replicates = 2)
#simplex centroid design giving 2^(p1) distinct design points
#(default response added with NA's)
mixDesign(p = 3, n = 2, type = "centroid")
#simplex centroid design with augmented points (default response added with NA's)
mixDesign(p = 3, n = 2, type = "centroid", axial = TRUE)
#yarn elongation example from Cornell (2002)
mdo = mixDesign(3,2, center = FALSE, axial = FALSE, randomize = FALSE,
replicates = c(1,1,2,3))
#set names (optional)
names(mdo) = c("polyethylene", "polystyrene", "polypropylene")
#units(mdo) = "%" #set units (optional)
#set response (i.e. yarn elongation)
elongation = c(11.0, 12.4, 15.0, 14.8, 16.1, 17.7, 16.4, 16.6, 8.8, 10.0, 10.0,
9.7, 11.8, 16.8, 16.0)
response(mdo) = elongation
#print a summary of the design
summary(mdo)
#show contourPlot and wirePlot
dev.new(14, 14);par(mfrow = c(2,2))
contourPlot3(A, B, C, elongation, data = mdo, form = "quadratic")
wirePlot3(A, B, C, elongation, data = mdo, form = "quadratic", theta = 190)
wirePlot3(A, B, C, elongation, data = mdo, form = "quadratic", phi = 390,
theta = 0)
wirePlot3(A, B, C, elongation, data = mdo, form = "quadratic", phi = 90)

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