'[Wekalist] Re: discretization in weka'

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List:       wekalist
Subject:    [Wekalist] Re: discretization in weka
From:       Eibe Frank <eibe () waikato ! ac ! nz>
Date:       2020-05-23 4:15:02
Message-ID: A71FF039-951E-4E4B-937B-0077B54798A3 () waikato ! ac ! nz
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Take a look at Chapter 6 of our data mining book \
(https://www.cs.waikato.ac.nz/~ml/weka/book.html \
<https://www.cs.waikato.ac.nz/~ml/weka/book.html>), for example.

C4.5 (J48 in WEKA) performs local discretisation of a numeric attribute into two \
intervals by finding the split point that maximises information gain (considering \
only the data at the node to be split).

Cheers,
Eibe

> On 23/05/2020, at 1:19 AM, haseulingbambu@gmail.com wrote:
> 
> Hello,
> 
> I have a question about discretization in j48. In manual calculation we usually \
> determine data into some groups (ex: high/medium/low). how does weka determine the \
> groups' limit (especially if the data are all numeric) while the groups are not \
> manually defined from the beginning?  
> Thanks in advance.
> _______________________________________________
> Wekalist mailing list -- wekalist@list.waikato.ac.nz
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[Attachment #5 (unknown)]

<html><head><meta http-equiv="Content-Type" content="text/html; \
charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: \
space; line-break: after-white-space;" class="">Take a look at Chapter 6 of our data \
mining book (<a href="https://www.cs.waikato.ac.nz/~ml/weka/book.html" \
class="">https://www.cs.waikato.ac.nz/~ml/weka/book.html</a>), for example.<div \
class=""><br class=""></div><div class="">C4.5 (J48 in WEKA) performs local \
discretisation of a numeric attribute into two intervals by finding the split point \
that maximises information gain (considering only the data at the node to be \
split).</div><div class=""><br class=""></div><div class="">Cheers,</div><div \
class="">Eibe<br class=""><div><br class=""><blockquote type="cite" class=""><div \
class="">On 23/05/2020, at 1:19 AM, <a href="mailto:haseulingbambu@gmail.com" \
class="">haseulingbambu@gmail.com</a> wrote:</div><br \
class="Apple-interchange-newline"><div class=""><div class="">Hello,<br class=""><br \
class="">I have a question about discretization in j48. In manual calculation we \
usually determine data into some groups (ex: high/medium/low). how does weka \
determine the groups' limit (especially if the data are all numeric) while the groups \
are not manually defined from the beginning? <br class=""><br class="">Thanks in \
advance.<br class="">_______________________________________________<br \
class="">Wekalist mailing list -- <a href="mailto:wekalist@list.waikato.ac.nz" \
class="">wekalist@list.waikato.ac.nz</a><br class="">Send posts to <a \
href="mailto:wekalist@list.waikato.ac.nz" class="">wekalist@list.waikato.ac.nz</a><br \
class="">To unsubscribe send an email to <a \
href="mailto:wekalist-leave@list.waikato.ac.nz" \
class="">wekalist-leave@list.waikato.ac.nz</a><br class="">To subscribe, unsubscribe, \
etc., visit <a href="https://list.waikato.ac.nz/postorius/lists/wekalist.list.waikato.ac.nz" \
class="">https://list.waikato.ac.nz/postorius/lists/wekalist.list.waikato.ac.nz</a><br \
class="">List etiquette: <a \
href="http://www.cs.waikato.ac.nz/~ml/weka/mailinglist_etiquette.html" \
class="">http://www.cs.waikato.ac.nz/~ml/weka/mailinglist_etiquette.html</a><br \
class=""></div></div></blockquote></div><br class=""></div></body></html>



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