# Dactyl: Edgeworth's counts of dactyls in Virgil's Aeneid In HistData: Data Sets from the History of Statistics and Data Visualization

## Description

Edgeworth (1885) took the first 75 lines in Book XI of Virgil's Aeneid and classified each of the first four "feet" of the line as a dactyl (one long syllable followed by two short ones) or not.

Grouping the lines in blocks of five gave a 4 x 25 table of counts, represented here as a data frame with ordered factors, `Foot` and `Lines`. Edgeworth used this table in what was among the first examples of analysis of variance applied to a two-way classification.

## Usage

 `1` ```data(Dactyl) ```

## Format

A data frame with 60 observations on the following 3 variables.

`Foot`

an ordered factor with levels `1` < `2` < `3` < `4`

`Lines`

an ordered factor with levels `1:5` < `6:10` < `11:15` < `16:20` < `21:25` < `26:30` < `31:35` < `36:40` < `41:45` < `46:50` < `51:55` < `56:60` < `61:65` < `66:70` < `71:75`

`count`

number of dactyls

## Source

Stigler, S. (1999) Statistics on the Table Cambridge, MA: Harvard University Press, table 5.1.

## References

Edgeworth, F. Y. (1885). On methods of ascertaining variations in the rate of births, deaths and marriages. Journal of the [Royal] Statistical Society, 48, 628-649.

## Examples

 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15``` ```data(Dactyl) # display the basic table xtabs(count ~ Foot+Lines, data=Dactyl) # simple two-way anova anova(dact.lm <- lm(count ~ Foot+Lines, data=Dactyl)) # plot the lm-quartet op <- par(mfrow=c(2,2)) plot(dact.lm) par(op) # show table as a simple mosaicplot mosaicplot(xtabs(count ~ Foot+Lines, data=Dactyl), shade=TRUE) ```

### Example output

```    Lines
Foot 1:5 6:10 11:15 16:20 21:25 26:30 31:35 36:40 41:45 46:50 51:55 56:60 61:65
1   3    3     5     5     4     4     2     2     2     1     2     4     3
2   1    4     0     3     3     3     5     2     2     4     3     1     2
3   1    2     4     2     5     2     1     2     2     2     0     2     2
4   2    2     1     0     3     1     2     0     2     1     1     2     1
Lines
Foot 66:70 71:75
1     2     4
2     3     2
3     0     1
4     1     0
Analysis of Variance Table

Response: count
Df Sum Sq Mean Sq F value    Pr(>F)
Foot       3 27.650  9.2167  6.5499 0.0009826 ***
Lines     14 20.233  1.4452  1.0271 0.4467408
Residuals 42 59.100  1.4071
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
```

HistData documentation built on May 31, 2017, 2:57 a.m.