prepare.data: Initial Preparations of Bitext before the Word Alignment and...

In word.alignment: Computing Word Alignment Using IBM Model 1 (and Symmetrization) for a Given Parallel Corpus and Its Evaluation

Description

For a given Sentence-Aligned Parallel Corpus, it prepars sentence pairs as an input for align.ibm1 and evaluation functions in this package.

Usage

prepare.data(file.sorc, file.trgt, n = -1L, 
             encode.sorc = 'unknown' , encode.trgt = 'unknown', 
             min.len = 5, max.len = 40, remove.pt = TRUE, word.align = TRUE)

Arguments

file.sorc	the name of source language file.
file.trgt	the name of target language file.
n	the number of sentences to be read.If -1, it considers all sentences.
encode.sorc	encoding to be assumed for the source language. If the value is "latin1" or "UTF-8" it is used to mark character strings as known to be in Latin-1 or UTF-8. For more details please see scan function.
encode.trgt	encoding to be assumed for the target language. If the value is "latin1" or "UTF-8" it is used to mark character strings as known to be in Latin-1 or UTF-8. For more details please see scan function.
min.len	a minimum length of sentences.
max.len	a maximum length of sentences.
remove.pt	logical. If TRUE, it removes all punctuation marks.
word.align	logical. If FALSE, it divides each sentence into its words. Results can be used in align.symmet, cross.table, align.test and evaluation functions.

Details

It balances between source and target language as much as possible. For example, it removes extra blank sentences and equalization sentence pairs. Also, using nfirst2lower function, it converts the first letter of each sentence into lowercase. Moreover, it removes short and long sentences.

Value

A list.

if word_align = TRUE

len1	An integer.
aa	A matrix (n*2), where n is the number of remained sentence pairs after preprocessing.

otherwise,

initial	An integer.
used	An integer.
source.tok	A list of words for each the source sentence.
target.tok	A list of words for each the target sentence.

Note

Note that if there is a few proper nouns in the parallel corpus, we suggest you to set all=TRUE to convert all text into lowercase.

Author(s)

Neda Daneshgar and Majid Sarmad.

References

Koehn P. (2010), "Statistical Machine Translation.", Cambridge University, New York.

See Also

evaluation, nfirst2lower, align.ibm1, scan

Examples

# Since the extraction of  bg-en.tgz in Europarl corpus is time consuming, 
# so the aforementioned unzip files have been temporarily exported to 
# http://www.um.ac.ir/~sarmad/... .
## Not run: 

aa1 = prepare.data ('http://www.um.ac.ir/~sarmad/word.a/euro.bg',
                   'http://www.um.ac.ir/~sarmad/word.a/euro.en', 
                    n = 20, encode.sorc = 'UTF-8')
 
aa2 = prepare.data ('http://www.um.ac.ir/~sarmad/word.a/euro.bg',
                   'http://www.um.ac.ir/~sarmad/word.a/euro.en', 
                    n = 20, encode.sorc = 'UTF-8', word.align = FALSE)
                   
aa3 = prepare.data ('http://www.um.ac.ir/~sarmad/word.a/euro.bg',
                   'http://www.um.ac.ir/~sarmad/word.a/euro.en', 
                    n = 20, encode.sorc = 'UTF-8', remove.pt = FALSE)

## End(Not run)

word.alignment documentation built on May 1, 2019, 10:21 p.m.