[ 
https://issues.apache.org/jira/browse/SPARK-5571?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14630871#comment-14630871
 ] 

Alok Singh commented on SPARK-5571:
-----------------------------------

Hi Feynman,

Sorry for the delay and gap, here at work , we had some training and few 
internal updates/changes and was not able to respond.


Here are my thoughts , please comments

stemmer
------------
I think we will need the stemmer module too. I was thinking we can just create 
a wrapper over the Lucene EnglishAnalyzer Or the OpenNLP stemmer. This can be 
seperate transformer  jira under the 'ml' tag
Without this component, we will have a lot of edges and nodes in the created 
graphx.

Stopword
------------
we can support two ways
- in one user give the list of stop words
-in another, we calculate it using the idf with tfi-idf transformer. We could 
create the new transformer which under the hood calls the tfi-df transformer 
with the filter range. This can also be another transformer jira under 'ml' tag.

The  LDA.runText
----------------------------------
The core LDA.runText method can be under the mllib tag and can be easier with 
the assumption that 
the input bag of words just need to be passed to a  CountVectorizer and then to 
LDA.run.
which will be implemented as per the description.

The complete pipeline
-----------------------------
User can create it's own pipeline using ml but I think we should create the 
TextLDA_Pipeline which will combine the above steps together and put it under 
'ml' tag jira


What are your thoughts [~josephkb] and [~fliang]

Alok


> LDA should handle text as well
> ------------------------------
>
>                 Key: SPARK-5571
>                 URL: https://issues.apache.org/jira/browse/SPARK-5571
>             Project: Spark
>          Issue Type: Improvement
>          Components: MLlib
>    Affects Versions: 1.3.0
>            Reporter: Joseph K. Bradley
>
> Latent Dirichlet Allocation (LDA) currently operates only on vectors of word 
> counts.  It should also supporting training and prediction using text 
> (Strings).
> This plan is sketched in the [original LDA design 
> doc|https://docs.google.com/document/d/1kSsDqTeZMEB94Bs4GTd0mvdAmduvZSSkpoSfn-seAzo/edit?usp=sharing].
> There should be:
> * runWithText() method which takes an RDD with a collection of Strings (bags 
> of words).  This will also index terms and compute a dictionary.
> * dictionary parameter for when LDA is run with word count vectors
> * prediction/feedback methods returning Strings (such as 
> describeTopicsAsStrings, which is commented out in LDA currently)



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

---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]

Reply via email to