Very good eye! I used "m = matrix("1 2 3 0 0 0 7 8 9 0 0 0", rows=4,
cols=3)" to generate the mm file, so the 4th row did indeed contain all
zeros.On Mon, Feb 15, 2016 at 4:50 PM, Shirish Tatikonda < shirish.tatiko...@gmail.com> wrote: > Btw (Just to be precise), in your example of "mm" file.. the metadata is "4 > 3 6" but the following non-zero values are only up to row number 3. So, > either it was a typo or the 4th row contains all zeros. > > > > On Mon, Feb 15, 2016 at 4:26 PM, Shirish Tatikonda < > shirish.tatiko...@gmail.com> wrote: > > > Both "mm" and "text" formats are identical except for a couple of > > differences: > > > > 1) for "mm": the matrix metadata is included in the first two lines; and > > for "text": the metadata is present in the associated .mtd file > > 2) "mm" data must be in a single file (i.e., no *part* files) where > > "text" data can span multiple *part* files (like any other file on HDFS). > > > > The support for "mm" is created mainly for the purpose of > > importing/exporting data in the format that R likes. > > > > Shirish > > > > On Mon, Feb 15, 2016 at 4:17 PM, Deron Eriksson <deroneriks...@gmail.com > > > > wrote: > > > >> Hi, > >> > >> I have a question with regards to text vs mm. Isn't the mm coordinate > >> format identical to the text format but the mm data file happens to > >> include > >> the metadata line for rows, cols, and nnzs, so shouldn't they scale the > >> same since the text row values (i,j,v) correspond to the mm rows? > >> > >> If we have the following MM: > >> %%MatrixMarket matrix coordinate real general > >> 4 3 6 > >> 1 1 1.0 > >> 1 2 2.0 > >> 1 3 3.0 > >> 3 1 7.0 > >> 3 2 8.0 > >> 3 3 9.0 > >> > >> The corresponding text format (with accompanying metadata file) is: > >> 1 1 1.0 > >> 1 2 2.0 > >> 1 3 3.0 > >> 3 1 7.0 > >> 3 2 8.0 > >> 3 3 9.0 > >> > >> So aren't these formats essentially the same? > >> > >> Deron > >> > >> > >> On Mon, Feb 15, 2016 at 3:56 PM, Matthias Boehm <mbo...@us.ibm.com> > >> wrote: > >> > >> > The meta data file is still useful in order to get the format. In case > >> of > >> > matrix market, errors will be raised if included meta data is > >> inconsistent. > >> > So no, we should not disallow to specify the meta data. In general, we > >> > anyway recommend using text (textcell) instead mm (matrix market) for > >> > scalability reasons. > >> > > >> > Regards, > >> > Matthias > >> > > >> > [image: Inactive hide details for Deron Eriksson ---02/15/2016 > 03:45:46 > >> > PM---Hi, The Matrix Market coordinate format contains # rows, #]Deron > >> > Eriksson ---02/15/2016 03:45:46 PM---Hi, The Matrix Market coordinate > >> > format contains # rows, # columns, and # > >> > > >> > From: Deron Eriksson <deroneriks...@gmail.com> > >> > To: dev@systemml.incubator.apache.org > >> > Date: 02/15/2016 03:45 PM > >> > Subject: Matrix Market format with metadata file > >> > ------------------------------ > >> > > >> > > >> > > >> > Hi, > >> > > >> > The Matrix Market coordinate format contains # rows, # columns, and # > >> > non-zero values as metadata near the top of a matrix data file. > >> > > >> > If I write a matrix in mm format using SystemML, no metadata file is > >> > created since the metadata is stored within the data file. > >> > > >> > However, when reading a matrix with mm format, I can supply a metadata > >> > file, even though metadata exists in the matrix data file. Is there > any > >> > reason for this, or should this be disallowed since the metadata file > is > >> > redundant and can cause confusion, since metadata values can then be > >> > specified in two places, which then brings up the question, "which > >> metadata > >> > value should be used"? > >> > > >> > Deron > >> > > >> > > >> > > >> > > > > >
