Yeah, +1 on the wrapper idea.

> Labels are certainly valuable (esp. for text) and if they are

> somehow built

> into the matrix lib, it will make the user's life easier. I share

> similar

> concerns w/ Ted and think his idea for a LabelWrapper class is a

> great idea.

>

> Jason

>

> On Sun, Mar 16, 2008 at 5:28 PM, Ted Dunning <

[hidden email]>

> wrote:

>

>>

>> I have been batting that question back and forth in my own head

>> recently.

>>

>> It IS absolutely a huge help to have labels. R has the data.frame

>> to do

>> this and it helps enormously. I have done it in some applications

>> and it

>> saved endless hassle.

>>

>> On the other hand, there is a real danger that the label

>> functionality

>> would

>> get sucked into a single implementation. Labels really are an

>> orthogonal

>> concern that are (should be) independent of how the matrix is

>> implemented.

>>

>> So should there really be something like a LabeledMatrix wrapper that

>> provides this labeling service to any matrix?

>>

>>

>> On 3/16/08 2:23 PM, "Grant Ingersoll (JIRA)" <

[hidden email]> wrote:

>>

>>>

>>> [

>>>

>>

https://issues.apache.org/jira/browse/MAHOUT-6?page=com.atlassian.jira.plugin>> .

>>>

>> system.issuetabpanels:comment-

>> tabpanel&focusedCommentId=12579261#action_125792

>>> 61 ]

>>>

>>> Grant Ingersoll commented on MAHOUT-6:

>>> --------------------------------------

>>>

>>> Does it make sense to be able to assign labels to the rows and

>>> columns

>> and

>>> maybe even have it accessible as a map? For instance, I think I

>>> could

>> use

>>> these for the bayesian classifier implementation I am working on

>>> and it

>> would

>>> make sense to be able to label the features and the labels.

>>> Naturally,

>> I can

>>> store the information elsewhere as well, but didn't know whether

>>> it made

>> sense

>>> to keep the info w/ the matrix.

>>>

>>>> Need a matrix implementation

>>>> ----------------------------

>>>>

>>>> Key: MAHOUT-6

>>>> URL:

https://issues.apache.org/jira/browse/MAHOUT-6>>>> Project: Mahout

>>>> Issue Type: New Feature

>>>> Reporter: Ted Dunning

>>>> Assignee: Grant Ingersoll

>>>> Attachments: MAHOUT-6a.diff, MAHOUT-6b.diff, MAHOUT-6c.diff,

>>>> MAHOUT-6d.diff, MAHOUT-6e.diff, MAHOUT-6f.diff, MAHOUT-6g.diff,

>>>> MAHOUT-6h.patch, MAHOUT-6i.diff, MAHOUT-6j.diff, MAHOUT-6k.diff,

>>>> MAHOUT-6l.patch

>>>>

>>>>

>>>> We need matrices for Mahout.

>>>> An initial set of basic requirements includes:

>>>> a) sparse and dense support are required

>>>> b) row and column labels are important

>>>> c) serialization for hadoop use is required

>>>> d) reasonable floating point performance is required, but awesome

>>>> FP is

>> not

>>>> e) the API should be simple enough to understand

>>>> f) it should be easy to carve out sub-matrices for sending to

>>>> different

>>>> reducers

>>>> g) a reasonable set of matrix operations should be supported, these

>> should

>>>> eventually include:

>>>> simple matrix-matrix and matrix-vector and matrix-scalar linear

>> algebra

>>>> operations, A B, A + B, A v, A + x, v + x, u + v, dot(u, v)

>>>> row and column sums

>>>> generalized level 2 and 3 BLAS primitives, alpha A B + beta C

>>>> and A

>> u +

>>>> beta v

>>>> h) easy and efficient iteration constructs, especially for sparse

>> matrices

>>>> i) easy to extend with new implementations

>>

>>

>

>

> --

> Jason Rennie

> Head of Machine Learning Technologies, StyleFeeder

>

http://www.stylefeeder.com/> Samantha's blog & pictures:

http://samanthalyrarennie.blogspot.com/