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Project Description 3 Latent Semantic Index. Compute TFIDF(token_i, document_j) = tf(ti; dj) log |Tr|/|Tr(ti) The token in each file is sorted and attached.

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Presentation on theme: "Project Description 3 Latent Semantic Index. Compute TFIDF(token_i, document_j) = tf(ti; dj) log |Tr|/|Tr(ti) The token in each file is sorted and attached."— Presentation transcript:

1 Project Description 3 Latent Semantic Index

2 Compute TFIDF(token_i, document_j) = tf(ti; dj) log |Tr|/|Tr(ti) The token in each file is sorted and attached the TFIDF value

3 1. Tr(ti)= the # of documents in Tr in which ti occurs at least once,  =1 + log(N(ti; dj)) if N(ti; dj) > 0 2. tf(ti; dj)   =0 otherwise 3. N(ti, dj) = the frequency of ti in dj.

4 Project 1. Tr(ti)= the # of documents in Tr in which ti occurs at least once,  =1 + log(N(ti; dj)) if N(ti; dj) > 0 2. tf(ti; dj)   =0 otherwise 3. N(ti, dj) = the frequency(normalization) of ti in dj.

5 Important point about Token TFIDF(token_i, document_j) = tf(ti; dj) log |Tr|/|Tr(ti) Correction(only consider (threshold2??) >=Tr(ti) >= threshold1 Discuss come properties about this numerical values Stemization( call system dictionary)

6 Create a Token Database Organize all Inverted files of the following documents http: //kdd.ics.uci.edu/databases/20newsgroups/20newsgroups.html into a database

7 LSI example token  document  !aDumb D10.901.2 D2000

8 High Dimension LSI example token  document  Dumb!aDumb D1 D2

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