> On 2011-12-13 13:08:20, Ted Dunning wrote: > > /trunk/core/src/main/java/org/apache/mahout/math/hadoop/DistributedRowMatrix.java, > > line 199 > > <https://reviews.apache.org/r/3147/diff/5/?file=64279#file64279line199> > > > > I would really rather use standard terminology here. > > > > A mean row is a row that is that average of all others, but a row mean > > would mean an average of the elements a single row. The plural form, row > > means, indicates the means of all rows. What you are computing are the > > means of every column. > > > > In contrast, R, Octave and Matlab all use columnMeans as the name of > > the function being implemented here.
Sure. In Matlab/Octave I'm used to mean(A,1) (takes the mean across the 1st dimension, ie. across rows, but done per column). I'll change this to colMeans(), which seems to be clearer. > On 2011-12-13 13:08:20, Ted Dunning wrote: > > /trunk/core/src/main/java/org/apache/mahout/math/hadoop/MatrixRowMeanJob.java, > > lines 129-132 > > <https://reviews.apache.org/r/3147/diff/5/?file=64280#file64280line129> > > > > There are lots of lines with trailing white space. Isn't this easily > > suppressed? I can use sed, or perhaps there's a better way? - Raphael ----------------------------------------------------------- This is an automatically generated e-mail. To reply, visit: https://reviews.apache.org/r/3147/#review3874 ----------------------------------------------------------- On 2011-12-13 04:46:47, Raphael Cendrillon wrote: > > ----------------------------------------------------------- > This is an automatically generated e-mail. To reply, visit: > https://reviews.apache.org/r/3147/ > ----------------------------------------------------------- > > (Updated 2011-12-13 04:46:47) > > > Review request for mahout, lancenorskog and Dmitriy Lyubimov. > > > Summary > ------- > > Here's a patch with a simple job to calculate the row mean (column-wise > mean). One outstanding issue is the combiner, this requires a wrtiable class > IntVectorTupleWritable, where the Int stores the number of rows, and the > Vector stores the column-wise sum. > > > This addresses bug MAHOUT-923. > https://issues.apache.org/jira/browse/MAHOUT-923 > > > Diffs > ----- > > > /trunk/core/src/main/java/org/apache/mahout/math/hadoop/DistributedRowMatrix.java > 1213474 > > /trunk/core/src/main/java/org/apache/mahout/math/hadoop/MatrixRowMeanJob.java > PRE-CREATION > > /trunk/core/src/test/java/org/apache/mahout/math/hadoop/TestDistributedRowMatrix.java > 1213474 > > Diff: https://reviews.apache.org/r/3147/diff > > > Testing > ------- > > Junit test > > > Thanks, > > Raphael > >
