Extract Rules from 'rpart' Object

Extract rules from an rpart object. This can be useful, if the rules must be implemented in another system. The rules contain all the criteria for the binary splits of an rpart tree from the root node down to the specified leaf.

Usage

Rules(x, node = NULL, leafonly = FALSE)

Arguments

x: the rpart object to extract the rules from
node: integer vector, defining the nodes whose details are required.
leafonly: boolean, defining if only the rules leading to end nodes ("leafs") should be returned.

Details

The function builds upon the original function path.rpart, which is bulky in some situations.

Value

a list with the rules

frame: the frame of the rpart
ylevels: the y values of the node
ds.size: the size of the dataset
path: a list of character vecotrs containing the rules

Author

Andri Signorell <andri@signorell.net>

Examples

r.rp <- FitMod(diabetes ~ ., data=d.pima, fitfn="rpart")
Rules(r.rp)
#> 
#>  Rule number: 1 
#> 
#>  Rule number: 2 
#>    glucose< 127.5
#> 
#>  Rule number: 4 [yval=neg cover=271 (35%) prob=0.08]
#>    glucose< 127.5
#>    age< 28.5
#> 
#>  Rule number: 5 
#>    glucose< 127.5
#>    age>=28.5
#> 
#>  Rule number: 10 [yval=neg cover=41 (5%) prob=0.05]
#>    glucose< 127.5
#>    age>=28.5
#>    mass< 26.35
#> 
#>  Rule number: 11 
#>    glucose< 127.5
#>    age>=28.5
#>    mass>=26.35
#> 
#>  Rule number: 22 [yval=neg cover=55 (7%) prob=0.18]
#>    glucose< 127.5
#>    age>=28.5
#>    mass>=26.35
#>    glucose< 99.5
#> 
#>  Rule number: 23 
#>    glucose< 127.5
#>    age>=28.5
#>    mass>=26.35
#>    glucose>=99.5
#> 
#>  Rule number: 46 
#>    glucose< 127.5
#>    age>=28.5
#>    mass>=26.35
#>    glucose>=99.5
#>    pedigree< 0.561
#> 
#>  Rule number: 92 [yval=neg cover=21 (3%) prob=0.19]
#>    glucose< 127.5
#>    age>=28.5
#>    mass>=26.35
#>    glucose>=99.5
#>    pedigree< 0.561
#>    pedigree< 0.2
#> 
#>  Rule number: 93 
#>    glucose< 127.5
#>    age>=28.5
#>    mass>=26.35
#>    glucose>=99.5
#>    pedigree< 0.561
#>    pedigree>=0.2
#> 
#>  Rule number: 186 
#>    glucose< 127.5
#>    age>=28.5
#>    mass>=26.35
#>    glucose>=99.5
#>    pedigree< 0.561
#>    pedigree>=0.2
#>    pregnant>=1.5
#> 
#>  Rule number: 372 [yval=neg cover=40 (5%) prob=0.30]
#>    glucose< 127.5
#>    age>=28.5
#>    mass>=26.35
#>    glucose>=99.5
#>    pedigree< 0.561
#>    pedigree>=0.2
#>    pregnant>=1.5
#>    pressure>=67
#> 
#>  Rule number: 373 [yval=pos cover=12 (2%) prob=0.75]
#>    glucose< 127.5
#>    age>=28.5
#>    mass>=26.35
#>    glucose>=99.5
#>    pedigree< 0.561
#>    pedigree>=0.2
#>    pregnant>=1.5
#>    pressure< 67
#> 
#>  Rule number: 187 [yval=pos cover=11 (1%) prob=0.82]
#>    glucose< 127.5
#>    age>=28.5
#>    mass>=26.35
#>    glucose>=99.5
#>    pedigree< 0.561
#>    pedigree>=0.2
#>    pregnant< 1.5
#> 
#>  Rule number: 47 [yval=pos cover=34 (4%) prob=0.74]
#>    glucose< 127.5
#>    age>=28.5
#>    mass>=26.35
#>    glucose>=99.5
#>    pedigree>=0.561
#> 
#>  Rule number: 3 
#>    glucose>=127.5
#> 
#>  Rule number: 6 
#>    glucose>=127.5
#>    mass< 29.95
#> 
#>  Rule number: 12 [yval=neg cover=41 (5%) prob=0.15]
#>    glucose>=127.5
#>    mass< 29.95
#>    glucose< 145.5
#> 
#>  Rule number: 13 
#>    glucose>=127.5
#>    mass< 29.95
#>    glucose>=145.5
#> 
#>  Rule number: 26 [yval=neg cover=21 (3%) prob=0.38]
#>    glucose>=127.5
#>    mass< 29.95
#>    glucose>=145.5
#>    insulin< 14.5
#> 
#>  Rule number: 27 [yval=pos cover=14 (2%) prob=0.71]
#>    glucose>=127.5
#>    mass< 29.95
#>    glucose>=145.5
#>    insulin>=14.5
#> 
#>  Rule number: 7 
#>    glucose>=127.5
#>    mass>=29.95
#> 
#>  Rule number: 14 
#>    glucose>=127.5
#>    mass>=29.95
#>    glucose< 157.5
#> 
#>  Rule number: 28 
#>    glucose>=127.5
#>    mass>=29.95
#>    glucose< 157.5
#>    age< 30.5
#> 
#>  Rule number: 56 
#>    glucose>=127.5
#>    mass>=29.95
#>    glucose< 157.5
#>    age< 30.5
#>    pressure>=61
#> 
#>  Rule number: 112 [yval=neg cover=31 (4%) prob=0.23]
#>    glucose>=127.5
#>    mass>=29.95
#>    glucose< 157.5
#>    age< 30.5
#>    pressure>=61
#>    mass< 41.8
#> 
#>  Rule number: 113 [yval=pos cover=9 (1%) prob=0.67]
#>    glucose>=127.5
#>    mass>=29.95
#>    glucose< 157.5
#>    age< 30.5
#>    pressure>=61
#>    mass>=41.8
#> 
#>  Rule number: 57 [yval=pos cover=10 (1%) prob=1.00]
#>    glucose>=127.5
#>    mass>=29.95
#>    glucose< 157.5
#>    age< 30.5
#>    pressure< 61
#> 
#>  Rule number: 29 [yval=pos cover=65 (8%) prob=0.72]
#>    glucose>=127.5
#>    mass>=29.95
#>    glucose< 157.5
#>    age>=30.5
#> 
#>  Rule number: 15 [yval=pos cover=92 (12%) prob=0.87]
#>    glucose>=127.5
#>    mass>=29.95
#>    glucose>=157.5
#>