Mailing-List: contact hama-dev-help@incubator.apache.org; run by ezmlm
Precedence: bulk
Reply-To: hama-dev@incubator.apache.org
Message-ID: <75011586.1237169990551.JavaMail.jira@brutus>
Date: Sun, 15 Mar 2009 19:19:50 -0700 (PDT)
From: "Edward J. Yoon (JIRA)" <jira@apache.org>
To: hama-dev@incubator.apache.org
Subject: [jira] Created: (HAMA-174) Compute the transpose of a matrix
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit

Compute the transpose of a matrix
---------------------------------

                 Key: HAMA-174
                 URL: https://issues.apache.org/jira/browse/HAMA-174
             Project: Hama
          Issue Type: Improvement
          Components: implementation, mapred 
    Affects Versions: 0.1.0
            Reporter: Edward J. Yoon
             Fix For: 0.1.0


The transpose of a matrix is another matrix in which the rows and columns have been reversed. The matrix must be square for this work.

| a11 a12 a13 |    | a11 a21 a31 |
| a21 a22 a23 | => | a12 a22 a32 |
| a31 a32 a33 |    | a13 a23 a33 |

- A map task receives a row n as a key, and vector of each row as its value
 - emit (Reversed index, the entry with the given index)

ex) row = 1, { 1: a11, 2: a12, 3: a13 }

a11, a11
a21, a12
a31, a13
...

- Reduce task sets the reversed values

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.