[jira] [Created] (SPARK-10127) Add numpy-like indexing interface for DenceMatrix

["Hiroshi Takahashi (JIRA)" <ji...@apache.org>]

Hiroshi Takahashi created SPARK-10127:
-----------------------------------------

             Summary: Add numpy-like indexing interface for DenceMatrix
                 Key: SPARK-10127
                 URL: https://issues.apache.org/jira/browse/SPARK-10127
             Project: Spark
          Issue Type: New Feature
          Components: MLlib
            Reporter: Hiroshi Takahashi


Currently, we don't have good interface to access sub-matrix.
It's inconvenience to prototype manipulate matrix via spark-shell for the reason.

My suggestion is to add operator "!" as operator of accessing sub-matrix instead of numpy's ().

for example:
{code}
scala> import org.apache.spark.mllib.linalg.DenseMatrix
import org.apache.spark.mllib.linalg.DenseMatrix

scala> val dm = new DenseMatrix(3, 3, Array(1.0, 4.0, 7.0, 2.0, 5.0, 8.0, 3.0, 6.0, 9.0))
dm: org.apache.spark.mllib.linalg.DenseMatrix = 
1.0  2.0  3.0  
4.0  5.0  6.0  
7.0  8.0  9.0  

// get row
scala> dm!(1)
res0: org.apache.spark.mllib.linalg.DenseMatrix = 4.0  5.0  6.0  

// get (i, j)
scala> dm!(1, 2)
res1: Double = 6.0

// get colmun
scala> dm!((), 1)
res2: org.apache.spark.mllib.linalg.DenseMatrix = 
2.0  
5.0  
8.0  

// get columns between i and j-1
scala> dm!((), (1, 3))
res3: org.apache.spark.mllib.linalg.DenseMatrix = 
2.0  3.0  
5.0  6.0  
8.0  9.0  

// get rows between i and j-1
scala> dm!((1, 3))
res4: org.apache.spark.mllib.linalg.DenseMatrix = 
4.0  5.0  6.0  
7.0  8.0  9.0  

// get sub-matrix between (i1, j1-1) and (i2, j2-1)
scala> dm!((1, 3), (1, 3))
res5: org.apache.spark.mllib.linalg.DenseMatrix = 
5.0  6.0  
8.0  9.0  
{code}



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

---------------------------------------------------------------------
To unsubscribe, e-mail: issues-unsubscribe@spark.apache.org
For additional commands, e-mail: issues-help@spark.apache.org