Mailing List Archive: MLTQuery not working; seeking debugging tips

I am having difficulty using MoreLikeThisQuery with an n-gram analyzer as its
analyzer.
A test query isn't hitting any document in a unit test case.
Is there any debugging method to use to understand why there is not hit?

Because the test code uses a RAMDirectory, I cannot use Luke to see if the index
was made correctly.

This is a snippet of the query code:

MoreLikeThisQuery mltQuery = new MoreLikeThisQuery(queryText, new String[]
{"source"}, //TODO: Make this array constant defaultFuzzyAnalyzer, "source"); //
defaultFuzzyAnalyzer is a 4-gram analyzer based on NGramTokenFilter.
mltQuery.setMinTermFrequency(1); mltQuery.setMinDocFreq(1);
mltQuery.setPercentTermsToMatch(threshold);mltQuery.setMaxQueryTerms(Integer.MAX_VALUE);
TopDocs topDocs = indexSearcher.search(mltQuery, max);

Thanks.

TK

I don't know why the code block in my first post lost newlines. Let me try again:

MoreLikeThisQuery mltQuery = new MoreLikeThisQuery(queryText, new String[]
{"source"}, defaultFuzzyAnalyzer, "source"); // defaultFuzzyAnalyzer is a 4-gram
analyzer based on NGramTokenFilter.

mltQuery.setMinTermFrequency(1);

mltQuery.setMinDocFreq(1);

mltQuery.setPercentTermsToMatch(threshold);

mltQuery.setMaxQueryTerms(Integer.MAX_VALUE);

TopDocs topDocs = indexSearcher.search(mltQuery, max);

But after posting this, I realized that I could use IndexSearcher#explain() as:

Explanation expl = indexSearcher.explain(mltQuery, docId);
System.out.printf("docId=%d; expl=%s\n", docId, expl.toString());

If there are better ways to debug, please let me know.

TK

On 5/20/21 9:51 PM, TK Solr wrote:
> I am having difficulty using MoreLikeThisQuery with an n-gram analyzer as its
> analyzer.
> A test query isn't hitting any document in a unit test case.
> Is there any debugging method to use to understand why there is not hit?
>
> Because the test code uses a RAMDirectory, I cannot use Luke to see if the
> index was made correctly.
>
> This is a snippet of the query code:
>
> MoreLikeThisQuery mltQuery = new MoreLikeThisQuery(queryText, new String[]
> {"source"}, //TODO: Make this array constant defaultFuzzyAnalyzer, "source");
> // defaultFuzzyAnalyzer is a 4-gram analyzer based on NGramTokenFilter.
> mltQuery.setMinTermFrequency(1); mltQuery.setMinDocFreq(1);
> mltQuery.setPercentTermsToMatch(threshold);mltQuery.setMaxQueryTerms(Integer.MAX_VALUE);
> TopDocs topDocs = indexSearcher.search(mltQuery, max);
>
>
>
> Thanks.
>
> TK
>
>