nori_number token filter
editnori_number token filter
editThe nori_number token filter normalizes Korean numbers
to regular Arabic decimal numbers in half-width characters.
Korean numbers are often written using a combination of Hangul and Arabic numbers with various kinds of punctuation. For example, ３．２천 means 3200. This filter does this kind of normalization and allows a search for 3200 to match ３．２천 in text, but can also be used to make range facets based on the normalized numbers and so on.
Notice that this analyzer uses a token composition scheme and relies on punctuation tokens
being found in the token stream.
Please make sure your nori_tokenizer has discard_punctuation set to false.
In case punctuation characters, such as U+FF0E(．), is removed from the token stream,
this filter would find input tokens ３ and ２천 and give outputs 3 and 2000 instead of 3200,
which is likely not the intended result.
If you want to remove punctuation characters from your index that are not part of normalized numbers,
add a stop token filter with the punctuation you wish to remove after nori_number in your analyzer chain.
Below are some examples of normalizations this filter supports. The input is untokenized text and the result is the single term attribute emitted for the input.
- 영영칠 → 7
- 일영영영 → 1000
- 삼천2백2십삼 → 3223
- 일조육백만오천일 → 1000006005001
- ３.２천 → 3200
- １.２만３４５.６７ → 12345.67
- 4,647.100 → 4647.1
- 15,7 → 157 (be aware of this weakness)
For example:
PUT nori_sample
{
"settings": {
"index": {
"analysis": {
"analyzer": {
"my_analyzer": {
"tokenizer": "tokenizer_discard_puncuation_false",
"filter": [
"part_of_speech_stop_sp", "nori_number"
]
}
},
"tokenizer": {
"tokenizer_discard_puncuation_false": {
"type": "nori_tokenizer",
"discard_punctuation": "false"
}
},
"filter": {
"part_of_speech_stop_sp": {
"type": "nori_part_of_speech",
"stoptags": ["SP"]
}
}
}
}
}
}
GET nori_sample/_analyze
{
"analyzer": "my_analyzer",
"text": "십만이천오백과 ３.２천"
}
Which results in:
{
"tokens" : [{
"token" : "102500",
"start_offset" : 0,
"end_offset" : 6,
"type" : "word",
"position" : 0
}, {
"token" : "과",
"start_offset" : 6,
"end_offset" : 7,
"type" : "word",
"position" : 1
}, {
"token" : "3200",
"start_offset" : 8,
"end_offset" : 12,
"type" : "word",
"position" : 2
}]
}