K2: Compute tree similarity

In autoharp: Semi-Automatic Grading of R and Rmd Scripts

Description

Compute tree similarity

Usage

K2(t1, t2, verbose = FALSE)

Arguments

t1	A TreeHarp object.
t2	A TreeHarp object.
verbose	A logical value, indicating if the output should be verbose.

Details

As far as possible, this function tries to do things recursively. It sets up a n x m matrix and fills up as much as it can. Then it uses recursive relationships to fill in the rest. When it cannot, it uses generate_all_subtrees to generate and count common subtrees.

Value

An integer, that counts the number of sub-trees in common between the two trees. Please see the reference papers for more information.

References

1. Convolution kernels for natural language, M Collins and N Duffy, Advances in neural information processing systems, 2002.

2. Convolution kernels on discrete structures, D Haussler, Technical report, Department of Computer Science, UC Santa Cruz, 1999.

Examples

tree1 <- TreeHarp(quote(x <- 1), TRUE)
tree2 <- TreeHarp(quote(y <- 1), TRUE)
K2(tree1, tree2, TRUE)

autoharp documentation built on Nov. 13, 2021, 1:06 a.m.