module CharDet

Big5 frequency table by Taiwan’s Mandarin Promotion Council <www.edu.tw:81/mandr/>

128 –> 0.42261 256 –> 0.57851 512 –> 0.74851 1024 –> 0.89384 2048 –> 0.97583

Ideal Distribution Ratio = 0.74851/(1-0.74851) =2.98 Random Distribution Ration = 512/(5401-512)=0.105

Typical Distribution Ratio about 25% of Ideal one, still much higher than RDR

BEGIN LICENSE BLOCK ########################

The Original Code is Mozilla Communicator client code.

Contributor(s):

Jeff Hodges - port to Ruby
Mark Pilgrim - port to Python

This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA

END LICENSE BLOCK #########################

BEGIN LICENSE BLOCK ########################

The Original Code is Mozilla Communicator client code.

Contributor(s):

Jeff Hodges
Mark Pilgrim - port to Python

END LICENSE BLOCK #########################

BEGIN LICENSE BLOCK ########################

The Original Code is Mozilla Communicator client code.

Contributor(s):

Jeff Hodges - port to Ruby
Mark Pilgrim - port to Python

END LICENSE BLOCK #########################

BEGIN LICENSE BLOCK ########################

The Original Code is Mozilla Universal charset detector code.

Contributor(s):

Jeff Hodges - port to Ruby
Mark Pilgrim - port to Python
Shy Shalom - original C code

END LICENSE BLOCK #########################

BEGIN LICENSE BLOCK ########################

The Original Code is mozilla.org code.

Contributor(s):

Jeff Hodges - port to Ruby
Mark Pilgrim - port to Python

END LICENSE BLOCK #########################

BEGIN LICENSE BLOCK ########################

The Original Code is Mozilla Universal charset detector code.

Contributor(s):

Jeff Hodges - port to Ruby
Mark Pilgrim - port to Python
Shy Shalom - original C code

END LICENSE BLOCK #########################

BEGIN LICENSE BLOCK ########################

The Original Code is mozilla.org code.

Contributor(s):

Jeff Hodges - port to Ruby
Mark Pilgrim - port to Python

END LICENSE BLOCK #########################

BEGIN LICENSE BLOCK ########################

The Original Code is mozilla.org code.

Contributor(s):

Jeff Hodges - port to Ruby
Mark Pilgrim - port to Python

END LICENSE BLOCK #########################

BEGIN LICENSE BLOCK ########################

The Original Code is mozilla.org code.

Contributor(s):

Jeff Hodges - port to Ruby
Mark Pilgrim - port to Python

END LICENSE BLOCK #########################

128 –> 0.79 256 –> 0.92 512 –> 0.986 1024 –> 0.99944 2048 –> 0.99999

Idea Distribution Ratio = 0.98653 / (1-0.98653) = 73.24 Random Distribution Ration = 512 / (2350-512) = 0.279.

Typical Distribution Ratio

BEGIN LICENSE BLOCK ########################

The Original Code is mozilla.org code.

Contributor(s):

Jeff Hodges - port to Ruby
Mark Pilgrim - port to Python

END LICENSE BLOCK #########################

128 –> 0.42261 256 –> 0.57851 512 –> 0.74851 1024 –> 0.89384 2048 –> 0.97583

Idea Distribution Ratio = 0.74851/(1-0.74851) =2.98 Random Distribution Ration = 512/(5401-512)=0.105

Typical Distribution Ratio about 25% of Ideal one, still much higher than RDR

BEGIN LICENSE BLOCK ########################

The Original Code is mozilla.org code.

Contributor(s):

Jeff Hodges - port to Ruby
Mark Pilgrim - port to Python

END LICENSE BLOCK #########################

512 –> 0.79 – 0.79 1024 –> 0.92 – 0.13 2048 –> 0.98 – 0.06 6768 –> 1.00 – 0.02

Ideal Distribution Ratio = 0.79135/(1-0.79135) = 3.79 Random Distribution Ration = 512 / (3755 - 512) = 0.157

Typical Distribution Ratio about 25% of Ideal one, still much higher that RDR

BEGIN LICENSE BLOCK ########################

The Original Code is mozilla.org code.

Contributor(s):

Jeff Hodges - port to Ruby
Mark Pilgrim - port to Python

END LICENSE BLOCK #########################

windows-1255 / ISO-8859-8 code points of interest

128 –> 0.77094 256 –> 0.85710 512 –> 0.92635 1024 –> 0.97130 2048 –> 0.99431

Ideal Distribution Ratio = 0.92635 / (1-0.92635) = 12.58 Random Distribution Ration = 512 / (2965+62+83+86-512) = 0.191

Typical Distribution Ratio, 25% of IDR

BEGIN LICENSE BLOCK ########################

The Original Code is Mozilla Communicator client code.

Contributor(s):

Jeff Hodges - port to Ruby
Mark Pilgrim - port to Python

END LICENSE BLOCK #########################

Character Mapping Table: this table is modified base on win1251BulgarianCharToOrderMap, so only number <64 is sure valid

BEGIN LICENSE BLOCK ########################

The Original Code is Mozilla Communicator client code.

Contributor(s):

Jeff Hodges - port to Ruby
Mark Pilgrim - port to Python

END LICENSE BLOCK #########################

BEGIN LICENSE BLOCK ########################

The Original Code is Mozilla Communicator client code.

Contributor(s):

Jeff Hodges - port to Ruby
Mark Pilgrim - port to Python

END LICENSE BLOCK #########################

BEGIN LICENSE BLOCK ########################

The Original Code is Mozilla Universal charset detector code.

The Initial Developer of the Original Code is

Simon Montagu

Contributor(s):

Jeff Hodges - port to Ruby
Mark Pilgrim - port to Python
Shy Shalom - original C code
Shoshannah Forbes - original C code (?)

END LICENSE BLOCK #########################

BEGIN LICENSE BLOCK ########################

The Original Code is Mozilla Communicator client code.

Contributor(s):

Jeff Hodges - port to Ruby
Mark Pilgrim - port to Python

END LICENSE BLOCK #########################

BEGIN LICENSE BLOCK ########################

The Original Code is Mozilla Communicator client code.

Contributor(s):

Jeff Hodges - port to Ruby
Mark Pilgrim - port to Python

END LICENSE BLOCK #########################

BEGIN LICENSE BLOCK ########################

The Original Code is Mozilla Universal charset detector code.

Contributor(s):

Jeff Hodges - port to Ruby
Mark Pilgrim - port to Python
Shy Shalom - original C code

END LICENSE BLOCK #########################

BEGIN LICENSE BLOCK ########################

The Original Code is Mozilla Universal charset detector code.

Contributor(s):

Jeff Hodges - port to Ruby
Mark Pilgrim - port to Python
Shy Shalom - original C code
Proofpoint, Inc.

END LICENSE BLOCK #########################

BEGIN LICENSE BLOCK ########################

The Original Code is Mozilla Universal charset detector code.

Contributor(s):

Jeff Hodges - port to Ruby
Mark Pilgrim - port to Python
Shy Shalom - original C code
Proofpoint, Inc.

END LICENSE BLOCK #########################

BEGIN LICENSE BLOCK ########################

The Original Code is mozilla.org code.

Contributor(s):

Jeff Hodges - port to Ruby
Mark Pilgrim - port to Python

END LICENSE BLOCK #########################

BEGIN LICENSE BLOCK ########################

The Original Code is Mozilla Universal charset detector code.

Contributor(s):

Jeff Hodges - port to Ruby
Mark Pilgrim - port to Python
Shy Shalom - original C code

END LICENSE BLOCK #########################

BEGIN LICENSE BLOCK ########################

The Original Code is Mozilla Universal charset detector code.

Contributor(s):

Jeff Hodges - port to Ruby
Mark Pilgrim - port to Python
Shy Shalom - original C code

END LICENSE BLOCK #########################

BEGIN LICENSE BLOCK ########################

The Original Code is mozilla.org code.

Contributor(s):

Jeff Hodges - port to Ruby
Mark Pilgrim - port to Python

END LICENSE BLOCK #########################

BEGIN LICENSE BLOCK ########################

The Original Code is Mozilla Universal charset detector code.

Contributor(s):

Jeff Hodges - port to Ruby
Mark Pilgrim - port to Python
Shy Shalom - original C code

END LICENSE BLOCK #########################

BEGIN LICENSE BLOCK ########################

The Original Code is mozilla.org code.

Contributor(s):

Jeff Hodges - port to Ruby
Mark Pilgrim - port to Python

END LICENSE BLOCK #########################

Constants

ACO
ACV
ASC
ASO
ASS
ASV
BIG5_TABLE_SIZE: Char to FreqOrder table
BIG5_TYPICAL_DISTRIBUTION_RATIO
BIG5_cls: BIG5
BIG5_st
Big5CharLenTable
Big5CharToFreqOrder
Big5SMModel
BulgarianLangModel: Model Table: total sequences: 100% first 512 sequences: 96.9392% first 1024 sequences:3.0618% rest sequences: 0.2992% negative sequences: 0.0020%
CLASS_NUM
DONT_KNOW
EDetecting
EError
EEscAscii
EFoundIt
EHighbyte
EItsMe
ENOUGH_DATA_THRESHOLD
ENOUGH_REL_THRESHOLD
ENotMe
EPureAscii
EStart
EUCJPCharLenTable
EUCJPSMModel
EUCJP_cls: EUC-JP
EUCJP_st
EUCKRCharLenTable
EUCKRCharToFreqOrder: Char to FreqOrder table ,
EUCKRSMModel
EUCKR_TABLE_SIZE
EUCKR_TYPICAL_DISTRIBUTION_RATIO
EUCKR_cls: EUC-KR
EUCKR_st
EUCTWCharLenTable
EUCTWCharToFreqOrder
EUCTWSMModel
EUCTW_TABLE_SIZE: Char to FreqOrder table ,
EUCTW_TYPICAL_DISTRIBUTION_RATIO
EUCTW_cls: EUC-TW
EUCTW_st
FINAL_KAF
FINAL_MEM
FINAL_NUN
FINAL_PE
FINAL_TSADI
FREQ_CAT_NUM
GB18030CharLenTable: To be accurate, the length of class 6 can be either 2 or 4. But it is not necessary to discriminate between the two since it is used for frequency analysis only, and we are validing each code range there as well. So it is safe to set it to be 2 here.
GB18030CharToFreqOrder
GB18030SMModel
GB18030_TABLE_SIZE
GB18030_TYPICAL_DISTRIBUTION_RATIO
GB18030_cls: GB18030
GB18030_st
GreekLangModel: Model Table: total sequences: 100% first 512 sequences: 98.2851% first 1024 sequences:1.7001% rest sequences: 0.0359% negative sequences: 0.0148%
HZCharLenTable
HZSMModel
HZ_cls
HZ_st
HebrewLangModel: Model Table: total sequences: 100% first 512 sequences: 98.4004% first 1024 sequences: 1.5981% rest sequences: 0.087% negative sequences: 0.0015%
HungarianLangModel: Model Table: total sequences: 100% first 512 sequences: 94.7368% first 1024 sequences:5.2623% rest sequences: 0.8894% negative sequences: 0.0009%
IBM855_CharToOrderMap
IBM866_CharToOrderMap
ISO2022CNCharLenTable
ISO2022CNSMModel
ISO2022CN_cls
ISO2022CN_st
ISO2022JPCharLenTable
ISO2022JPSMModel
ISO2022JP_cls
ISO2022JP_st
ISO2022KRCharLenTable
ISO2022KRSMModel
ISO2022KR_cls
ISO2022KR_st
Ibm855Model
Ibm866Model
JISCharToFreqOrder
JIS_TABLE_SIZE: Char to FreqOrder table ,
JIS_TYPICAL_DISTRIBUTION_RATIO
JP2_CHAR_CONTEXT: This is hiragana 2-char sequence table, the number in each cell represents its frequency category
KOI8R_CharToOrderMap: KOI8-R language model Character Mapping Table:
Koi8rModel
LOGICAL_HEBREW_NAME
Latin1ClassModel: 0 : illegal 1 : very unlikely 2 : normal 3 : very likely
Latin1_CharToClass
Latin2HungarianModel
Latin2_HungarianCharToOrderMap: Character Mapping Table:
Latin5BulgarianModel
Latin5CyrillicModel
Latin5_BulgarianCharToOrderMap
Latin7GreekModel
Latin7_CharToOrderMap: Character Mapping Table:
MAX_REL_THRESHOLD
MINIMUM_DATA_THRESHOLD
MINIMUM_THRESHOLD
MIN_FINAL_CHAR_DISTANCE: Minimum Visual vs Logical final letter score difference. If the difference is below this, don’t rely solely on the final letter score distance.
MIN_MODEL_DISTANCE: Minimum Visual vs Logical model score difference. If the difference is below this, don’t rely at all on the model score distance.
MacCyrillicModel
NEGATIVE_SHORTCUT_THRESHOLD
NORMAL_KAF
NORMAL_MEM
NORMAL_NUN
NORMAL_PE
NORMAL_TSADI
NUMBER_OF_SEQ_CAT
NUM_OF_CATEGORY
ONE_CHAR_PROB
OTH
POSITIVE_CAT
POSITIVE_SHORTCUT_THRESHOLD
RussianLangModel: Model Table: total sequences: 100% first 512 sequences: 97.6601% first 1024 sequences: 2.3389% rest sequences: 0.1237% negative sequences: 0.0009%
SAMPLE_SIZE
SB_ENOUGH_REL_THRESHOLD
SHORTCUT_THRESHOLD
SJISCharLenTable
SJISSMModel
SJIS_cls: Shift_JIS
SJIS_st
SURE_NO
SURE_YES
SYMBOL_CAT_ORDER
TIS620CharToOrderMap: Character Mapping Table:
TIS620ThaiModel
ThaiLangModel: Model Table: total sequences: 100% first 512 sequences: 92.6386% first 1024 sequences:7.3177% rest sequences: 1.0230% negative sequences: 0.0436%
UCS2BECharLenTable
UCS2BESMModel
UCS2BE_cls: UCS2-BE
UCS2BE_st
UCS2LECharLenTable
UCS2LESMModel
UCS2LE_cls: UCS2-LE
UCS2LE_st
UDF
UTF8CharLenTable
UTF8SMModel
UTF8_cls: UTF-8
UTF8_st
VERSION
VISUAL_HEBREW_NAME
Win1250HungarianCharToOrderMap
Win1250HungarianModel
Win1251BulgarianModel
Win1251CyrillicModel
Win1253GreekModel
Win1253_CharToOrderMap
Win1255HebrewModel
Win1255_CharToOrderMap: Windows-1255 language model Character Mapping Table:

Public Class Methods

detect (aBuf)

Source

# File lib/rchardet.rb, line 58
def CharDet.detect(aBuf)
  aBuf = aBuf.dup.force_encoding(Encoding::BINARY)

  u = UniversalDetector.new
  u.reset
  u.feed(aBuf)
  u.close
  u.result
end