// this actually does a matrixB.transpose.times(matrixA)
Path cooccurrenceMatrixPath = getTempPath(CO_OCCURRENCE_MATRIX);
ToolRunner.run(getConf(), new MatrixMultiplicationJob(), new String[]{
"--numRowsA", Integer.toString(numberOfUsers),
"--numColsA", Integer.toString(numberOfItems),
"--numRowsB", Integer.toString(numberOfUsers),
"--numColsB", Integer.toString(numberOfItems),
"--inputPathA", matrixBPath.toString(),
"--inputPathB", matrixAPath.toString(),
// huh, no option of this name???? todo: do we have to find it after the mult?
"--outputPath", cooccurrenceMatrixPath.toString(),
"--tempDir", tempPath.toString(),
});
// now [B'A] will be transposed before the multiply so we need to transpose twice?
// calculating [B'A]H_v by first transposing the [B'A] then creating the multiply job but
// H_v is A' (a users view history vectors are column vectors) so we have to transpose both [B'A] and A
// since the multiply will automatically transpose the first matrix (not sure why but it does).
ToolRunner.run(getConf(), new TransposeJob(), new String[]{
"--input", cooccurrenceMatrixPath.toString(),
"--numRows", Integer.toString(numberOfUsers),
"--numCols", Integer.toString(numberOfItems),
"--tempDir", tempPath.toString(),
});
Path transposedBTransposeAMatrixPath = findMostRecentPath(tempPath, "transpose");
ToolRunner.run(getConf(), new MatrixMultiplicationJob(), new String[]{
"--inputPathA", transposedBTransposeAMatrixPath.toString(),//[B'A]'
"--numRowsA", Integer.toString(numberOfItems),
"--numColsA", Integer.toString(numberOfItems),
"--inputPathB", matrixATransposePath.toString(),
"--numRowsB", Integer.toString(numberOfItems),