There is a way: http://hadoop.apache.org/common/docs/r0.18.3/mapred_tutorial.html#DistributedCache
Are you working with a sparse matrix, or a full one? On Apr 22, 2011, at 2:33 PM, aanghelescu wrote: > > Hi all, > > I am trying to perform matrix-vector multiplication using Hadoop. > > So I have matrix M in a file, and vector v in another file. Obviously, files > are of different sizes. Is it possible to make it so that each Map task will > get the whole vector v and a chunk of matrix M? I know how my map and reduce > functions should look like, but I don't know how to format the input. > > Basically I want my map function to output key-value pairs (i,m[i,j]*v(j)), > where i is the row number, and j the column number; v(j) is the jth element > in v. And the reduce function will sum up all the values with the same key - > i, and that will be the ith element of my result vector. > > Or can you suggest another way to do it? > > Thanks, > Alexandra > -- > View this message in context: > http://old.nabble.com/providing-the-same-input-to-more-than-one-Map-task-tp31459012p31459012.html > Sent from the Hadoop core-user mailing list archive at Nabble.com. >
