Awesome
CLD - Compact Language Detector
This package contains the CLD (Compact Language Detection) library, extracted from the source code for Google's Chromium library at http://src.chromium.org/svn/trunk/src/third_party/cld, specifically revision 105735. The original extraction was done by Mike McCandless and was altered to improve the build and packaging as well as add new bindings for various languages.
The LICENSE is the same as Chromium's LICENSE and is included in the LICENSE file for reference.
Installing the C++ library
Prerequisites
Building the C++ library requires a C++ compiler (duh) as well as pkg-config
so future programs can locate the needed dependancies.
Building
The shared C++ library can be built from source using the following commands:
$ git clone git://github.com/mzsanford/cld.git
$ cd cld
$ libtoolize
$ ./configure
$ automake --add-missing
$ make
$ make check # optional. Runs the tests
Installing
Once built from source:
$ make install
Or, Mac OSX users of Homebrew can build and install via:
$ brew install https://raw.github.com/mzsanford/homebrew/libcld/Library/Formula/libcld.rb
Ports
None of the ports are 100% completed yet but the preliminary APIs are introduced below
Ruby
Prerequisites
The libcld
C++ library must be installed (see above)
Installing
# 'gem install ...' in the near future
$ git clone http://github.com/mzsanford/cld.git
$ cd cld/ports/ruby
$ rake gem
$ gem install pkg/*gem
Example
require 'CLD'
require 'pp' # just for illustration
cld = CLD::Detector.new
res = cld.detect_language('I am the very measure of a modern major general')
pp res
#<CLD::LanguageResult:0x007fb7728b6768
@possible_languages=
[#<CLD::PossibleLanguage:0x007fb7728b6628
@language=#<CLD::Language:0x007fb7728b66a0 @code="en", @name="ENGLISH">,
@raw_score=100.0,
@score=52.6742301458671>],
@probable_language=
#<CLD::Language:0x007fb7728b6740 @code="en", @name="ENGLISH">,
@reliable=0>
Documentation
Full RDoc documentation is at http://mzsanford.github.com/cld/ports/ruby/rdoc/index.html and includes even more examples.
Node
Prerequisites
The libcld
C++ library must be installed (see above). Tested with node version 10.0.26
.
Installing
$ cd /PATH/FOR/CLD
$ git clone http://github.com/mzsanford/cld.git
$ cd cld/ports/node
$ make -f Makefile.example test
$ cd PATH/FOR/YOUR/PROJECT
$ npm install /PATH/FOR/CLD/cld/ports/node
Example
Assuming you're in /PATH/FOR/YOUR/PROJECT
above:
var LanguageDetector = require("cld/cld.node").LanguageDetector;
var detector = new LanguageDetector();
// Sync - Returns two letter language code of the most likely candidate language
var simpleResult = detector.detectSync("This is my sample text");
// Returns 'en' in this case
// Async - Returns detailed result structure
detector.detect("This is my sample text", function(result) {
// 'result' contains:
// { languageCode: 'en',
// reliable: false,
// details:
// [ { languageCode: 'en', normalizedScore: 20.25931928687196, percentScore: 64 },
// { languageCode: 'fr', normalizedScore: 8.221993833504625, percentScore: 36 },
// { languageCode: 'un', normalizedScore: 0, percentScore: 0 } ] }
});
Documentation
Both the detectSync
and detect
methods take an option second parameter that is a hash of options. The available options (and defaults) are:
-
tld
(none): The TLD of the domain that the data came from. This is used as a hint for some ambiguous languages, for example the following snippet from there tests:var detector = new LanguageDetector(); var ambig = " 常用漢字 "; detector.detectSync(ambig) #=> "zh-TW" detector.detectSync(ambig, { tld: "cn" }) #=> "zh" detector.detectSync(ambig, { tld: "jp" }) #=> "ja"
-
html
(false
): The string to be processed HTML. If this is the case then markup will be ignored in the calculations. -
allowExtendedLanguages
(true
): Return language from outside of the core set of supported languages (where wuality is not as good) -
pickSummaryLanguage
(false
): If true then the summary language may not be the top match, based on some other factors. -
skipWeakMatches
(false
): Include weak matches in the results
Java
As a JNI library the Java port may require some environment settings to work correctly. For example on a fresh Ubuntu install I needed to install the Oracle JDK, set JAVA_HOME
and LD_LIBRARY_PATH
for linking and compilation to work correctly.
Prerequisites
The libcld
C++ library must be installed (see above). See the notes above about compilation and runtime linker environments.
Installing
# Maven repository information in the future
$ git clone http://github.com/mzsanford/cld.git
$ cd cld/ports/java
# mvn test (optional)
$ mvn install
Example
CompactLanguageDetector compactLanguageDetector = new CompactLanguageDetector();
LanguageDetectionResult result = compactLanguageDetector.detect("This is my sample text");
if (result.isReliable()) {
// getProbableLocale returns a java.util.Locale
System.out.println("Pretty sure that's " + result.getProbableLocale().getDisplayName());
} else {
for (LanguageDetectionCandidate candidate : result.getCandidates()) {
System.out.println("Maybe it's " + candidate.getLocale().getDisplayName());
}
}
Documentation
Full Javadocs are at http://mzsanford.github.com/cld/ports/java/doc/apidocs.
Python
Prerequisites
The libcld
C++ library must be installed (see above)
Installing
$ git clone http://github.com/mzsanford/cld.git
$ cd cld/ports/python
$ make install # This will prompt for your password
Example
import cld
detectedLangName, detectedLangCode, isReliable, textBytesFound, details = cld.detect("This is my sample text", pickSummaryLanguage=True, removeWeakMatches=False)
print ' detected: %s' % detectedLangName
print ' reliable: %s' % (isReliable != 0)
print ' textBytes: %s' % textBytesFound
print ' details: %s' % str(details)
# The output look lie so:
# detected: ENGLISH
# reliable: True
# textBytes: 25
# details: [('ENGLISH', 'en', 64, 20.25931928687196), ('FRENCH', 'fr', 36, 8.221993833504625)]
Documentation
Once you've compiled & installed the Python bindings detection is easy.
First, you must get your content (plain text or HTML) encoded into UTF8 bytes. Then, detect like this:
topLanguageName, topLanguageCode, isReliable, textBytesFound, details = cld.detect(bytes)
The code and name of the top language is returned. isReliable is True if the top language is much better than 2nd best language. textBytesFound tells you how many actual bytes CLD analyzed (after removing HTML tags, collapsing areas of too-many-spaces, etc.). details has an entry per top 3 languages that matched, that includes the percent confidence of the match as well as a separate normalized score.
The detect method takes optional params:
-
isPlainText
(default is False): set to True if you know your bytes don't have any XML/HTML markup -
includeExtendedLanguages
(default is True): set to False to exclude "extended" languages added by Google -
hintTopLevelDomain
(default is None): set to the last part of the domain name that the content came from (for example if the URL was http://www.krasnahora.cz, pass the string 'cz'). This gives a hint that can bias the detector somewhat. -
hintLanguageCode
(default is None): set to the possible language. For example, if the web-server declared the language, or the content itself embedded an http-equiv meta tag declaring the language, pass this (for example, "it" for Italian). This gives a hint that can bias the detector somewhat. -
hintEncoding
(default is None): set to the original encoding of the content (note you still must pass UTF-8 encoded bytes). This gives a hint that can bias the detector somewhat. NOTE: this is currently not working. -
pickSummaryLanguage
(default is False): if False, CLD will always return the top matching language as the answer. If True, it will sometimes pick 2nd or 3rd match (for example, if English and X match, where X (not UNK) is big enough, assume the English is boilerplate and return X). In simple testing accuracy seems to suffer a bit (XX to YY %) when this is True so I've defaulted to False. -
removeWeakMatches
(default is True): if a match isn't strong enough, delete it. This ensures some amount of confidence when a language is returned.
The module exports these global constants:
-
cld.ENCODINGS
: list of the encoding names CLD recognizes (if you provide hintEncoding, it must be one of these names). -
cld.LANGUAGES
: list of languages and their codes (if you provide hintLanguageCode, it must be one of the codes from these codes). -
cld.EXTERNAL_LANGUAGES
: list of external languages and their codes. Note that external languages cannot be hinted, but may be matched if you pass includeExtendedLanguages=True (the default). -
cld.DETECTED_LANGUAGES
: list of all detectable languages, as best I can determine (this was reverse engineered from a unit test, ie it contains a language X if that language was tested and passes for at least one example text).