This Search Engine

2011-12-08

HW4 - MapReduce problem 14.7 .

'''Originally Posted By: sheetalg'''

The question asks to design a MapReduce that computes the conditional probability Pr[t1 | t2] of seeing the term t1 in a document that contains the term t2. So my questions are: 1. What will be the input to map function ? map(k, v) - What should be k and v ? (My guess is k = url, and v= docid) 2. How do you compute this probability ? My guess is P(a | b) = P (b | a) * P(a) / P (b). In this case as well, how do I compute P (b | a) ? 3. The question talks something about map function emitting secondary keys to enforce a certain ordering. Can you highlight what ordering is it talking about ? Thanks, Sheetal

'''Originally Posted By: sheetalg''' The question asks to design a MapReduce that computes the conditional probability Pr[t1 | t2] of seeing the term t1 in a document that contains the term t2. So my questions are: 1. What will be the input to map function ? map(k, v) - What should be k and v ? (My guess is k = url, and v= docid) 2. How do you compute this probability ? My guess is P(a | b) = P (b | a) * P(a) / P (b). In this case as well, how do I compute P (b | a) ? 3. The question talks something about map function emitting secondary keys to enforce a certain ordering. Can you highlight what ordering is it talking about ? Thanks, Sheetal

-- HW4 - MapReduce problem 14.7

'''Originally Posted By: sheetalg'''

Anyone, any clue ? Thanks, Sheetal

'''Originally Posted By: sheetalg''' Anyone, any clue ? Thanks, Sheetal