Hi Robin,
It looks like the linear regression model takes in a dataset not a matrix?
It would be helpful for this example if you could set up the whole problem
end to end using one of the columns of the matrix as b. So A is a sparse
matrix and b is a sparse vector
Best regards.
Iman
On Sun, Nov 6, 2016 at 6:43 AM <iman.mohtash...@gmail.com> wrote:
> Thank you! Would happen to have this code in Java?.
> This is extremely helpful!
>
>
> Iman
>
>
>
>
> On Sun, Nov 6, 2016 at 3:35 AM -0800, "Robineast [via Apache Spark User
> List]" <ml-node+s1001560n28027...@n3.nabble.com> wrote:
>
> Here’s a way of creating sparse vectors in MLLib:
>
> import org.apache.spark.mllib.linalg.Vectors
> import org.apache.spark.rdd.RDD
>
> val rdd = sc.textFile("A.txt").map(line => line.split(",")).
> map(ary => (ary(0).toInt, ary(1).toInt, ary(2).toDouble))
>
> val pairRdd: RDD[(Int, (Int, Int, Double))] = rdd.map(el => (el._1, el))
>
> val create = (first: (Int, Int, Double)) => (Array(first._2),
> Array(first._3))
> val combine = (head: (Array[Int], Array[Double]), tail: (Int, Int,
> Double)) => (head._1 :+ tail._2, head._2 :+ tail._3)
> val merge = (a: (Array[Int], Array[Double]), b: (Array[Int],
> Array[Double])) => (a._1 ++ b._1, a._2 ++ b._2)
>
> val A = pairRdd.combineByKey(create,combine,merge).map(el =>
> Vectors.sparse(3,el._2._1,el._2._2))
>
> If you have a separate file of b’s then you would need to manipulate this
> slightly to join the b’s to the A RDD and then create LabeledPoints. I
> guess there is a way of doing this using the newer ML interfaces but it’s
> not particularly obvious to me how.
>
> One point: In the example you give the b’s are exactly the same as col 2
> in the A matrix. I presume this is just a quick hacked together example
> because that would give a trivial result.
>
>
> -------------------------------------------------------------------------------
> Robin East
> *Spark GraphX in Action* Michael Malak and Robin East
> Manning Publications Co.
> http://www.manning.com/books/spark-graphx-in-action
>
>
>
>
>
> On 3 Nov 2016, at 18:12, im281 [via Apache Spark User List] <[hidden
> email] <http:///user/SendEmail.jtp?type=node&node=28027&i=0>> wrote:
>
> I would like to use it. But how do I do the following
> 1) Read sparse data (from text or database)
> 2) pass the sparse data to the linearRegression class?
>
> For example:
>
> Sparse matrix A
> row, column, value
> 0,0,.42
> 0,1,.28
> 0,2,.89
> 1,0,.83
> 1,1,.34
> 1,2,.42
> 2,0,.23
> 3,0,.42
> 3,1,.98
> 3,2,.88
> 4,0,.23
> 4,1,.36
> 4,2,.97
>
> Sparse vector b
> row, column, value
> 0,2,.89
> 1,2,.42
> 3,2,.88
> 4,2,.97
>
> Solve Ax = b???
>
>
>
> ------------------------------
> If you reply to this email, your message will be added to the discussion
> below:
>
> http://apache-spark-user-list.1001560.n3.nabble.com/mLIb-solving-linear-regression-with-sparse-inputs-tp28006p28008.html
> To start a new topic under Apache Spark User List, email [hidden email]
> <http:///user/SendEmail.jtp?type=node&node=28027&i=1>
> To unsubscribe from Apache Spark User List, click here.
> NAML
> <http://apache-spark-user-list.1001560.n3.nabble.com/template/NamlServlet.jtp?macro=macro_viewer&id=instant_html%21nabble%3Aemail.naml&base=nabble.naml.namespaces.BasicNamespace-nabble.view.web.template.NabbleNamespace-nabble.view.web.template.NodeNamespace&breadcrumbs=notify_subscribers%21nabble%3Aemail.naml-instant_emails%21nabble%3Aemail.naml-send_instant_email%21nabble%3Aemail.naml>
>
>
> Robin East
> Spark GraphX in Action Michael Malak and Robin East
> Manning Publications Co.
> http://www.manning.com/books/spark-graphx-in-action
>
>
> ------------------------------
> If you reply to this email, your message will be added to the discussion
> below:
>
> http://apache-spark-user-list.1001560.n3.nabble.com/mLIb-solving-linear-regression-with-sparse-inputs-tp28006p28027.html
> To unsubscribe from mLIb solving linear regression with sparse inputs, click
> here
> <http://apache-spark-user-list.1001560.n3.nabble.com/template/NamlServlet.jtp?macro=unsubscribe_by_code&node=28006&code=aW1hbi5tb2h0YXNoZW1pQGdtYWlsLmNvbXwyODAwNnwtMTc1OTAxNjQz>
> .
> NAML
> <http://apache-spark-user-list.1001560.n3.nabble.com/template/NamlServlet.jtp?macro=macro_viewer&id=instant_html%21nabble%3Aemail.naml&base=nabble.naml.namespaces.BasicNamespace-nabble.view.web.template.NabbleNamespace-nabble.view.web.template.NodeNamespace&breadcrumbs=notify_subscribers%21nabble%3Aemail.naml-instant_emails%21nabble%3Aemail.naml-send_instant_email%21nabble%3Aemail.naml>
>
>
--
View this message in context:
http://apache-spark-user-list.1001560.n3.nabble.com/mLIb-solving-linear-regression-with-sparse-inputs-tp28006p28029.html
Sent from the Apache Spark User List mailing list archive at Nabble.com.
