I have a list of many users (over 10 million) each of which is represented by a userid followed by 10 floating-point numbers indicating their preference. I would like to efficiently calculate the user similarity matrix using cosine similarity based on mapreduce. However, since the values are floating-point numbers, it is hard to determine a key in the mapreduce framework. Any suggestions?
Related Questions in HADOOP
- php Variable name must change in for loop
- register_shutdown_function is not getting called
- Query returning zero rows despite entries existing
- Retrieving *number* pages by page id
- Automatically closing tags in form input?
- How to resize images with PHP PARSE SDK
- how to send email from localhost using codeigniter?
- Mariadb max Error while sending QUERY packet PID
- Multiusers login redirect different page in php
- Imaginary folder when I use "DirectoryIterator" in PHP?
Related Questions in MAPREDUCE
- php Variable name must change in for loop
- register_shutdown_function is not getting called
- Query returning zero rows despite entries existing
- Retrieving *number* pages by page id
- Automatically closing tags in form input?
- How to resize images with PHP PARSE SDK
- how to send email from localhost using codeigniter?
- Mariadb max Error while sending QUERY packet PID
- Multiusers login redirect different page in php
- Imaginary folder when I use "DirectoryIterator" in PHP?
Related Questions in COSINE-SIMILARITY
- php Variable name must change in for loop
- register_shutdown_function is not getting called
- Query returning zero rows despite entries existing
- Retrieving *number* pages by page id
- Automatically closing tags in form input?
- How to resize images with PHP PARSE SDK
- how to send email from localhost using codeigniter?
- Mariadb max Error while sending QUERY packet PID
- Multiusers login redirect different page in php
- Imaginary folder when I use "DirectoryIterator" in PHP?
Popular Questions
- How do I undo the most recent local commits in Git?
- How can I remove a specific item from an array in JavaScript?
- How do I delete a Git branch locally and remotely?
- Find all files containing a specific text (string) on Linux?
- How do I revert a Git repository to a previous commit?
- How do I create an HTML button that acts like a link?
- How do I check out a remote Git branch?
- How do I force "git pull" to overwrite local files?
- How do I list all files of a directory?
- How to check whether a string contains a substring in JavaScript?
- How do I redirect to another webpage?
- How can I iterate over rows in a Pandas DataFrame?
- How do I convert a String to an int in Java?
- Does Python have a string 'contains' substring method?
- How do I check if a string contains a specific word?
Popular Tags
Trending Questions
- UIImageView Frame Doesn't Reflect Constraints
- Is it possible to use adb commands to click on a view by finding its ID?
- How to create a new web character symbol recognizable by html/javascript?
- Why isn't my CSS3 animation smooth in Google Chrome (but very smooth on other browsers)?
- Heap Gives Page Fault
- Connect ffmpeg to Visual Studio 2008
- Both Object- and ValueAnimator jumps when Duration is set above API LvL 24
- How to avoid default initialization of objects in std::vector?
- second argument of the command line arguments in a format other than char** argv or char* argv[]
- How to improve efficiency of algorithm which generates next lexicographic permutation?
- Navigating to the another actvity app getting crash in android
- How to read the particular message format in android and store in sqlite database?
- Resetting inventory status after order is cancelled
- Efficiently compute powers of X in SSE/AVX
- Insert into an external database using ajax and php : POST 500 (Internal Server Error)
I think the easiest solution would be the Mahout library. There are a couple of map-reduce similarity matrix jobs in Mahout that might work for your use case.
The first is Mahout's
ItemSimilarityJobthat is part of its recommender system libraries. The specific info for that job can be found here. You would simply need to provide the input data in the required format and choose yourVectorSimilarityMeasure(which for your case would be SIMILARITY_COSINE) along with any additional optimizations. Since you are looking to calculate user-user similarity based on a preference vector of ten floating point value, what you could do is assign a simple 1-to-10 numeric hash for the indices of the vector and generate a simple .csv file of vectorIndex, userID, decimalValue as input for the Mahout item-similarity job (the userID being a numeric Int or Long value). The resulting output should be a tab separated text file of userID,userID,similarity.A second solution might be Mahout's
RowSimilarityJobincluded in its math library. I've never used it myself, but some info can be found here and in this previous stackoverflow thread. Rather than a .csv as input, you would need to translate your input data as aDistributedRowMatrix, the userIDs being the rows of the matrix. The output, I believe, will also be aDistributedRowMatrixsequence file containing the user-user similarity data you are seeking.I suppose which solution is better depends on what input/output format you prefer. All the best.