Thanks Jason, yes, that’s true, but how to finish the first step
it seems that sc.textFile() has no parameters to achieve the goal,
I stored the file on s3
Best,
--
Nan Zhu
On Monday, January 6, 2014 at 11:27 PM, Jason Dai wrote:
> If you assign each file to a standalone partition, then you can generate the
> Rating RDD using something like the following:
>
> files.mapPartitions { part =>
> product = part.next()
> part.map((user, rating) => (user, product, rating))
> }
>
> Thanks,
> -Jason
>
>
>
> On Tue, Jan 7, 2014 at 1:17 AM, Nan Zhu <[email protected]
> (mailto:[email protected])> wrote:
> > Hi, all
> >
> > I meet a question related to how to share a variable among tasks, it seems
> > that neither broadcast nor accumulator can resolve my problem
> >
> > I have a set of txt files as my dataset, naming 1.txt - 20000.txt
> >
> > each txt file represents the rating of users to a certain product, the
> > product ID is indicated in the first line of each file, “1:”…”20000:”
> >
> > the following lines are ratings “userid, rating"
> >
> > I want to parse the input files with spark and pass it to the ALS
> > implementation in mllib
> >
> > the ALS requires me to have a RDD of Rating objects, where Rating is
> > 3-tuple (user, product, rating)
> >
> > My problem is that some tasks get the partition of a certain text file, so
> > it will never see the first line like “1:” so that it cannot get which
> > product the rating is corresponded to
> >
> > How can I resolve this, except getting some script to transform the format
> > of the files by appending the product id to each line?
> >
> > Best,
> >
> > --
> > Nan Zhu
> >
> >
> >
>
