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From "Sudarsan, Sithu D." <Sithu.Sudar...@fda.hhs.gov>
Subject RE: Lucene QueryParser and Analyzer
Date Thu, 29 Apr 2010 20:54:37 GMT
 
-------sample code-------------
>> Analyzer analyzer = new LingPipeAnalyzer();
>> Searcher searcher = new IndexSearcher(directory);
>> QueryParser qParser = new MultiFieldQueryParser(Version.LUCENE_30,
>> SEARCH_FIELDS, analyzer);
>> Query query = qParser.parse(queryLine[1]);
>> ScoreDoc[] results = searcher.search(query, TOP_N).scoreDocs;

qParser will use the analyzer LingPipeAnalyzer() before forming the
query.


Sincerely,
Sithu D Sudarsan


-----Original Message-----
From: Wei Ho [mailto:weiho@princeton.edu] 
Sent: Thursday, April 29, 2010 4:44 PM
To: java-user@lucene.apache.org
Subject: Re: Lucene QueryParser and Analyzer

Sorry, I guess "discarding the punctuation" was a bit misleading.
I meant that given the two input strings,

Input1: C1C2,C3C4,C5C6,C7,C8C9C10
Input2: C1C2  C3C4  C5C6  C7  C8C9C10

The analyzer I implemented tokenizes both Input1 and Input2 as "C1C2", 
"C3C4", "C5C6", "C7", "C8C9C10" - that is, it doesn't include the 
punctuation in the tokenization. I'm assuming that QueryParser is simply

passing the entire input string to the analyzer and taking the tokens, 
in which case Input1 and Input2 should be considered identifcal. Does 
QueryParser doing any sort of pre-processing or filtering beforehand? If

so, how can I turn it off?

Aside from stopping tokens at punctuations, my analyzer is also doing 
Chinese word segmentation, so I'd like to be sure that QueryParser is 
using the analyzer the way I expect it to.

Thanks,
Wei



-------- Original Message  --------
Subject: Re: Lucene QueryParser and Analyzer
From: Sudarsan, Sithu D. <Sithu.Sudarsan@fda.hhs.gov>
To: java-user@lucene.apache.org
Date: 4/29/2010 4:08 PM
>
> If so,
>
> Input1:  c1c2c3c4c5c6c7....
> Input2: c1c2 c3c4 ...
>
> I guess, they are different! Add a whitespace after commas and see if
> that works...
>
> Sincerely,
> Sithu D Sudarsan
>
>
> -----Original Message-----
> From: Wei Ho [mailto:weiho@princeton.edu]
> Sent: Thursday, April 29, 2010 4:04 PM
> To: java-user@lucene.apache.org
> Subject: Re: Lucene QueryParser and Analyzer
>
> No, there is no whitespace after the comma in Input1
>
> Input1: C1C2,C3C4,C5C6,C7,C8C9C10
> Input2: C1C2  C3C4  C5C6  C7  C8C9C10
>
> Input1 is basically one big long word with commas and Chinese
characters
>
> one after the other. Input2 is where I manually separated the string
> into the component terms by replacing the comma with whitespace. My
> confusion stems from the fact that I thought it should not matter
since
> the analyzer should be discarding the punctuation anyway? So the
> tokenization process should be the same for both Input1 and Input2? If
> that is not the case, what do I need to change?
>
> Thanks,
> Wei Ho
>
> -------- Original Message  --------
> Subject: Re: Lucene QueryParser and Analyzer
> From: Sudarsan, Sithu D.<Sithu.Sudarsan@fda.hhs.gov>
> To: java-user@lucene.apache.org
> Date: 4/29/2010 3:54 PM
>    
>> Hi,
>>
>> Is there a whitespace after the comma?
>>
>>
>> Sincerely,
>> Sithu D Sudarsan
>>
>>
>> -----Original Message-----
>> From: Wei Ho [mailto:weiho@princeton.edu]
>> Sent: Thursday, April 29, 2010 3:51 PM
>> To: java-user@lucene.apache.org
>> Subject: Lucene QueryParser and Analyzer
>>
>> Hello,
>>
>> I'm using Lucene to index and search through a collection of Chinese
>> documents. However, I'm noticing an odd behavior in query
>> parsing/searching.
>>
>> Given the two queries below:
>>
>> (Ci refers to Chinese character i)
>> Input1: C1C2,C3C4,C5C6,C7,C8C9C10
>> Input2: C1C2  C3C4  C5C6  C7  C8C9C10
>>
>> Input1 returns absolutely nothing, while Input2 (replacing the commas
>> with spaces) works as expected. I'm a bit confused why this would be
>> happening - it seems that QueryParser uses the Analyzer passed to it
>>      
> to
>    
>> tokenize the input query string, so if the Analyzer ignores the
>> punctuations, it seems that Input1 and Input2 should return identical
>> results. Is there some pre-Analyzer filtering or whatever that
>> QueryParser does? I've tried this with the StandardAnalyzer,
>> SmartChineseAnalyzer, and an analyzer that I implemented which
>> explicitly skips over punctuations and whitespaces in tokenizing the
>> query string, but to no avail.
>>
>> 
>> -----------------------------------
>>
>> I'm probably just doing something dumb, but any help would be greatly
>> appreciated!
>>
>> Thanks,
>> Wei Ho
>>
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>>
>>
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>>
>>      
>
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>
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>    


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