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/fingerprint/man/feat2bin.Rd

http://github.com/rajarshi/cdkr
Unknown | 42 lines | 38 code | 4 blank | 0 comment | 0 complexity | 1674c7179912857a1fc76dd81392d361 MD5 | raw file
 1\name{featvec.to.binaryfp}
 2\alias{featvec.to.binaryfp}
 3\title{
 4Convert a Set of Feature Fingerprints to Binary Fingerprints
 5}
 6\description{
 7Most feature vector style fingerprints (such as circular fingerprints) are
 8of variable length, with the features being pulled from an implicit (and 
 9very large) universe of features. 
10
11While it is possible to convert a single feature fingerprint to a binary vector 
12via a hashing procedure, one cannot convert the feature representation into 1:1 
13binary representation.
14
15However, for a collection of feature fingerprints, one can define a "local" universe
16as the union of the features contained in the set of fingerprints. With this definition
17each feature can be mapped to a single bit and thus each fingerprint can be converted
18to a fixed length, keyed fingerprint.
19
20Since circular fingerprints can lead to a very large binary fingerprint, the initial 
21fingerprint is usually folded multiple times to achieve a desired bit density.
22
23Since the fingerprint folding procedure divides a fingerprint into two equal halves and
24OR's the two halves together, the starting fingerprint must be of even length. For circular
25fingerprints that may not lead to an even-length initial bit string, an extra bit is added 
26at the top of the bit string.
27}
28\usage{
29featvec.to.binaryfp(fps, bit.length = 256)
30}
31\arguments{
32    \item{fps}{
33    A list of \code{featvec} objects
34    }
35    \item{bit.length}{The length of the bit string to stop folding at}
36}
37\value{
38A list of objects of class \code{fingerprint}
39}
40\seealso{\code{\link{fold}}}
41\keyword{logic}
42\author{Rajarshi Guha \email{rajarshi.guha@gmail.com}}