Engineers manipulated three factors (with 3, 2, and 4 levels each) in the construction and operation of printer rods, to see if they influenced the magnetic force around the rod.
A data frame with 44 observations on the following 14 variables.
||the magnetic force at each of the equally-spaces positions 1, 2, ..., 11 on the printer rod|
|| electric current passing through the rod, with
|| a factor identifying the configuration, with
|| a factor identifying the type of metal from
which the rod was made, with four levels
Ramsey, F.L. and Schafer, D.W. (2002). The Statistical Sleuth: A Course in Methods of Data Analysis (2nd ed), Duxbury.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
str(case1701) pca <- princomp(case1701[,1:11]) summary(pca) # The first 3 principal components account for 99.7% of the variation screeplot(pca) # The loadings suggest the following meaningful summaries... loadings(pca) overallaverage <- with(case1701, (L1 + L2 + L3 + L4 + L5 + L6 + L7 + L8 + L9 + L10 + L11)/11) rightleftdiff <- with(case1701, (L9 + L10 + L11)/3 - (L1 + L2 + L3)/3) middleleftdiff <- with(case1701, L6 - (L1 + L2)/2) # Note 4 clusters and 1 outlier pairs(cbind(overallaverage, rightleftdiff, middleleftdiff)) fit1 <- lm(overallaverage ~ Current*Configur*Material, case1701) anova(fit1)
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.