Description Usage Format Source Examples

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.

1 |

A data frame with 44 observations on the following 14 variables.

Name | Description |

`L1` , `L2` ,..., `L11` | the magnetic force at each of the equally-spaces positions 1, 2, ..., 11 on the printer rod |

`Current` | electric current passing through the rod, with
three levels `"0"` , `"250"` and `"500"` (milliamperes) |

`Configur` | a factor identifying the configuration, with
two levels `"0"` and `"1"` |

`Material` | a factor identifying the type of metal from
which the rod was made, with four levels `"1"` , `"2"` ,
`"3"` and `"4"` |

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)
``` |

Embedding an R snippet on your website

Add the following code to your website.

For more information on customizing the embed code, read Embedding Snippets.