« Return to Thread: posterior probability distribution from NaiveBayes

Re: posterior probability distribution from NaiveBayes

by Alex Speder :: Rate this Message:

On Thu, Feb 16, 2012 at 01:17, Kari Ruohonen <karruo@...> wrote:

> Hi,
> I found this old message chain answering how one can get the
> probabilities of predictions for a NaiveBayes model:
> ************************************************************
> On 13/08/11 1:15 AM, sara yadollahi wrote:
>> hi
>> how can I get probability estimate of every record of each classes in
>> naive Bayes classifier?
>
> Turn on "Output predictions" in the "More options" of the Classify panel
> in the Explorer. This can be used to output the probability distribution
> for each instance in the test set.
>
> Cheers,
> Mark.
> ************************************************************
>
> However, when I tried this I only get the probability of the predicted
> class. Is there a way to get probabilities for all classes? I am using
> weka 3.7.4 on Ubuntu 11.10.
>
> regards, Kari
>
>
>
>
> _______________________________________________
> Wekalist mailing list
> Send posts to: Wekalist@...
> List info and subscription status: https://list.scms.waikato.ac.nz/mailman/listinfo/wekalist
> List etiquette: http://www.cs.waikato.ac.nz/~ml/weka/mailinglist_etiquette.html
>

Hi Kari,

Assuming I understand your question correct, you're referring in
particular to the distribution table that was generated in earlier
versions of Weka. This output can still be generated but in a
somewhat less obvious way (for new users, in any case). Under "More
options..." there's an option labelled "Output predictions" which
defaults to "Null". To re-enabled older-style output, click "Choose"
and select "CSV". You will then need to configure the CSV output by
clicking on the box to the right of "Choose" which should now read
"CSV." The settings you'll want to change are "outputDistribution" to
"True" and "useTab" to "True."

Hope that helps!

--
Alex Speder
alex.speder@...

_______________________________________________
Wekalist mailing list
Send posts to: Wekalist@...
List info and subscription status: https://list.scms.waikato.ac.nz/mailman/listinfo/wekalist
List etiquette: http://www.cs.waikato.ac.nz/~ml/weka/mailinglist_etiquette.html

« Return to Thread: posterior probability distribution from NaiveBayes