dotplot.cubist {Cubist} R Documentation

Visualization of Cubist Rules and Equations

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 lattice::dotplot()

Details

For the splits, a panel is created for each predictor. The x-axis is the range of the predictor scaled to be between zero and one 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 lattice::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

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)))

[Package Cubist version 0.3.0 Index]