systemml-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Deron Eriksson <deroneriks...@gmail.com>
Subject Re: Matrix Market format with metadata file
Date Tue, 16 Feb 2016 00:57:06 GMT
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.tatikonda@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.tatikonda@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 <deroneriksson@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 <mboehm@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 <deroneriksson@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
> >> >
> >> >
> >> >
> >>
> >
> >
>

Mime
  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message