headers
Mark Hall | 1 Nov 2010 09:33
Favicon

Re: need help on using Linear SMO

On 30/10/10 9:07 AM, Hasan, Quazi M wrote:
> Hello Everyone,
>
> I am trying to use Linear SMO for my text classification. I did the
> following things to make it Linear:
>
> *SMO smoClassifier = new SMO();*
>
> *PolyKernel polyK = new PolyKernel();*
>
> **
>
> *polyK.setUseLowerOrder(false);*
>
> *polyK.setExponent(1.0);*
>
> *smoClassifier.setKernel(polyK);*
>
> *smoClassifier.buildClassifier(data);*
>
> *Evaluation eval = new Evaluation(trainData);*
>
> *eval.evaluateModel(smoClassifier, testInstances);*
>
> But, I’m getting very low *accuracy(26%).* Here the attributes in the
> arff file are all numeric values (the frequency of words). Could anyone
> tell me what I’m doing wrong?
>
> Thanks in advance.
(Continue reading)

Permalink | Reply |
headers
Hasan, Quazi M | 1 Nov 2010 15:48
Picon

RE: need help on using Linear SMO

Hi Mark,

Thanks for your response. Below you will find your question's answers:

1. How many classes has your data got? 

   Ans:I have 100 class labels.

2. Have you tried different values for the complexity parameter (c), turning off normalization (or
normalizing the vector length with weka.filters.unsupervised.instance.Normalize)? 

->For Complexity Parameter, I tried to use different values but, the highest accuracy I got after that is
49%. How will choose the value for "C" or on what basis do I need to vary the values of "C"?

->Normalization: I haven't tried normalization. What does normalization do? My features are numeric
values, which are frequency of words in text document.

3.How does NaiveBayesMultinomial perform on your data?

->With NaiveBayesMultinomial, I got 84% accuracy. Now to compare the result with NaiveBayes I'm using
SVM. SVM should perform better than NaiveBayes right?

4. Do I have to also set the epsilon value in Linear SVM? How will choose or try the different values of
Epsilon? Is there any boundary or base to select that value? Please help me.

Thanks,
-Quazi Hasan.

-----Original Message-----
From: wekalist-bounces <at> list.scms.waikato.ac.nz
(Continue reading)

Permalink | Reply |

Gmane