dotplot.cubist: Visualization of Cubist Rules and Equations

In Cubist: Rule- and Instance-Based Regression Modeling

Description

Lattice dotplots of the rule conditions or the linear model coefficients produced by cubist objects

Usage

## S3 method for class 'cubist'
dotplot(x, data = NULL, 
        what = "splits", committee = NULL, 
        rule = NULL, ...)

Arguments

x	a cubist object
data	not currently used (here for lattice compatibility)
what	either "splits" or "coefs"
committee	which committees to plot
rule	which rules to plot
...	options to pass to dotplot

Details

For the splits, a panel is created for each predictor. The x-axis is the range of the predictor scaled to [0, 1] and the y-axis has a line for each rule (within each committee). Areas are colored as based on their region. For example, if one rule has var1 < 10, the linear for this rule would be colored. If another rule had the complementary region of var1 <= 10, it would be on another line and shaded a different color.

For the coefficient plot, another dotplot is made. The layout is the same except the the x-axis is in the original units and has a dot if the rule used that variable in a linear model.

Value

a dotplot object

Author(s)

R code by Max Kuhn, original C sources by R Quinlan and modifications be Steve Weston

References

Quinlan. Learning with continuous classes. Proceedings of the 5th Australian Joint Conference On Artificial Intelligence (1992) pp. 343-348

Quinlan. Combining instance-based and model-based learning. Proceedings of the Tenth International Conference on Machine Learning (1993) pp. 236-243

Quinlan. C4.5: Programs For Machine Learning (1993) Morgan Kaufmann Publishers Inc. San Francisco, CA

http://rulequest.com/cubist-info.html

See Also

cubist, cubistControl, predict.cubist, summary.cubist, predict.cubist, dotplot

Examples

library(mlbench)
data(BostonHousing)

## 1 committee and no instance-based correction, so just an M5 fit:
mod1 <- cubist(x = BostonHousing[, -14], y = BostonHousing$medv)
dotplot(mod1, what = "splits")
dotplot(mod1, what = "coefs")

## Now with 10 committees
mod2 <- cubist(x = BostonHousing[, -14], y = BostonHousing$medv, committees = 10)
dotplot(mod2, scales = list(y = list(cex = .25)))
dotplot(mod2, what = "coefs", 
        between = list(x = 1, y = 1),
        scales = list(x = list(relation = "free"), 
                      y = list(cex = .25)))

Example output

Loading required package: lattice

Cubist documentation built on May 2, 2019, 6:16 p.m.