To whom it may concern:
I am trying a factorial design a system of mine that has two factors.
Each factor was set at four different levels, with one
replication for each of the combinations. My data is as follows:
A B Response
1 600 2.5 0.0257
2 600 2.5 0.0254
3 600 5 0.0217
4 600 5 0.0204
5 600 10 0.0191
6 600 10 0.0210
7 600 20 0.0133
8 600 20 0.0139
9 800 2.5 0.0312
10 800 2.5 0.0317
11 800 5 0.0307
12 800 5 0.0309
13 800 10 0.0330
14 800 10 0.0318
15 800 20 0.0225
16 800 20 0.0234
17 1000 2.5 0.0350
18 1000 2.5 0.0352
19 1000 5 0.0373
20 1000 5 0.0361
21 1000 10 0.0432
22 1000 10 0.0402
23 1000 20 0.0297
24 1000 20 0.0306
25 1200 2.5 0.0324
26 1200 2.5 0.0326
27 1200 5 0.0353
28 1200 5 0.0353
29 1200 10 0.0453
30 1200 10 0.0436
31 1200 20 0.0348
32 1200 20 0.0357
I am able to enter my data into R and obtain an ANOVA table
(which I have been able to verify as correct using an excel
spreadsheet), using the following syntax:
Factorial<-data.frame(A=c(rep(c("600", "600", "600", "600", "800",
"800", "800", "800", "1000", "1000", "1000", "1000", "1200",
"1200", "1200", "1200"), each=2)), B=c(rep(c("2.5", "5",
"10", "20", "2.5", "5", "10", "20", "2.5", "5", "10", "20",
"2.5", "5", "10", "20"), each=2)), Response = c(0.0257,
0.0254, 0.0217, 0.0204, 0.0191, 0.021, 0.0133, 0.0139,
0.0312, 0.0317, 0.0307, 0.0309, 0.033, 0.0318, 0.0225,
0.0234, 0.035, 0.0352, 0.0373, 0.0361, 0.0432, 0.0402,
0.0297, 0.0306, 0.0324, 0.0326, 0.0353, 0.0353, 0.0453,
0.0436, 0.0348, 0.0357))
anova(aov(Response~A*B, data=Factorial))
However, this is as far as I am able to go. I would like to
obtain the coefficients of my model, but am unable. I would
also like to use other non-linear models as these factors are
not linear. Also would like to add A^2 and B^2 into the ANOVA
and modeling.
Please can you help with regard and offer some advice. Your
help is much appreciated.
Yours sincerely,
Leslie Correia
------------------------------------------------
Department of Process Engineering
University of Stellenbosch
Private Bag X1
Matieland, 7602
Stellenbosch
Tel: 0837012017
E-mail: lcorreia at sun.ac.za <mailto:lcorreia at sun.ac.za>
------------------------------------------------
[[alternative HTML version deleted]]