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From Debasish Das <debasish.da...@gmail.com>
Subject Re: How to use Mahout VectorWritable in Spark.
Date Wed, 14 May 2014 14:37:39 GMT
You will get 10x speedup by not using mahout vector and use breeze sparse
vector from mllib in your mllib kmeans run....

@Xiangrui showed the comparison chart sometime back...
On May 14, 2014 6:33 AM, "Xiangrui Meng" <mengxr@gmail.com> wrote:

> You need
>
> > val raw = sc.sequenceFile(path, classOf[Text], classOf[VectorWriteable])
>
> to load the data. After that, you can do
>
> > val data = raw.values.map(_.get)
>
> To get an RDD of mahout's Vector. You can use `--jar mahout-math.jar`
> when you launch spark-shell to include mahout-math.
>
> Best,
> Xiangrui
>
> On Tue, May 13, 2014 at 10:37 PM, Stuti Awasthi <stutiawasthi@hcl.com>
> wrote:
> > Hi All,
> >
> > I am very new to Spark and trying to play around with Mllib hence
> apologies
> > for the basic question.
> >
> >
> >
> > I am trying to run KMeans algorithm using Mahout and Spark MLlib to see
> the
> > performance. Now initial datasize was 10 GB. Mahout converts the data in
> > Sequence File <Text,VectorWritable> which is used for KMeans Clustering.
> > The Sequence File crated was ~ 6GB in size.
> >
> >
> >
> > Now I wanted if I can use the Mahout Sequence file to be executed in
> Spark
> > MLlib for KMeans . I have read that SparkContext.sequenceFile may be used
> > here. Hence I tried to read my sequencefile as below but getting the
> error :
> >
> >
> >
> > Command on Spark Shell :
> >
> > scala> val data = sc.sequenceFile[String,VectorWritable]("/
> > KMeans_dataset_seq/part-r-00000",String,VectorWritable)
> >
> > <console>:12: error: not found: type VectorWritable
> >
> >        val data = sc.sequenceFile[String,VectorWritable]("
> > /KMeans_dataset_seq/part-r-00000",String,VectorWritable)
> >
> >
> >
> > Here I have 2 ques:
> >
> > 1.  Mahout has “Text” as Key but Spark is printing “not found: type:Text”
> > hence I changed it to String.. Is this correct ???
> >
> > 2. How will VectorWritable be found in Spark. Do I need to include Mahout
> > jar in Classpath or any other option ??
> >
> >
> >
> > Please Suggest
> >
> >
> >
> > Regards
> >
> > Stuti Awasthi
> >
> >
> >
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> >
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