Rank: 351 based on 190 downloads (last 30 days) and 3 files submitted
photo

Dimitrios Ververidis

E-mail
Company/University
Fraunhofer Institute IAIS Bonn

Personal Profile:

Dimitrios Ververidis was born in Karies, Leukada, Greece, in 1978. Finished at the high school of Thermi in 1996. He graduated from the dept. of Mathematics of Aristotle University of Thessaloniki in 2001. He graduated with the Master Degree of Medical Informatics of the same University in 2003. He has received the Ph.D. degree at the dept. of Informatics, Aristotle University of Thessaloniki in 2008. His research interests include speech emotion recognition and pattern classification.

More Information in my blog:
http://dimitriosververidis.blogspot.com/

Professional Interests:
Speech Processing, Emotion Recognition, Pattern Recognition, Multivariate Statistical Analysis

 

Watch this Author's files

 

Files Posted by Dimitrios View all
Updated   File Tags Downloads
(last 30 days)
Comments Rating
24 Feb 2011 Information loss of the Mahalanobis distance in high dimensions: Matlab implementation Information loss estimation to set a lower limit on classification rate. Author: Dimitrios Ververidis pattern recognition, gaussian methods, feature selection, information loss, high dimensionality p... 11 1
29 Aug 2010 Screenshot Feature Selection using Matlab Select the subset of features that maximizes Correct Classification Rate. Author: Dimitrios Ververidis demo, gui, signal processing, image processing, modeling 146 27
  • 3.44444
3.4 | 10 ratings
04 May 2009 Screenshot Gaussian Mixture Modeling GUI (GMM DEMO) GUI for an Expectation-Maximization algorithm (EM) variant (Split-EM-Discriminant) Author: Dimitrios Ververidis demo, mathematics, image processing, gui, optimization, signal processing 33 3
  • 4.0
4.0 | 1 rating
Comments and Ratings by Dimitrios View all
Updated File Comments Rating
09 Jan 2012 Feature Selection using Matlab Select the subset of features that maximizes Correct Classification Rate. Author: Dimitrios Ververidis

Go to options and make confidence interval smaller. This will increase the number of cross-validation repetitions, thus execution time gets longer. The features selected will be almost identical per run. This is due to the fact that cross-validation involves a random selection of training and testing set.

20 Sep 2010 Feature Selection using Matlab Select the subset of features that maximizes Correct Classification Rate. Author: Dimitrios Ververidis

Response to Ly Lu:

The problem is that you used 'test' instead of 'test.mat' and therefore matlab can not find your file.

check if stringvariable DatasetToUse is 'test.mat'

01 Mar 2010 Feature Selection using Matlab Select the subset of features that maximizes Correct Classification Rate. Author: Dimitrios Ververidis

Hi,

1)There is no missing end in the "DataLoadAndPreprocess.m". As regards the reduction of 114 features to 90, it is happening because there were some features with NaNs in the certain dataset that were removed.

You can remove such features (if you have NaNs of Infs in your data) by adding some lines in function DataLoadAndPreprocess.m.

2) Well, there was a minor bug:

At the ForwSel_main.mat replace lines 256 to 273 with the following:

    if ~isempty(handles)
        axes(handles.YelLinesAxes);
        hold on
        if (NPatterns > KFeatures)
            axis([0 NPatterns 0 KFeatures]); axis manual
            HYelLines(FeatureToInclude)=plot([0 NPatterns+2],...
                (FeatureToInclude-0.5)*ones(1,2),'y','linewidth',3);
        else
            axis([0 KFeatures 0 NPatterns]); axis manual
            HYelLines(FeatureToInclude)= plot(...
                FeatureToInclude*ones(1,2),[0 KFeatures+2],'y','linewidth',3);
        end
        set(gca,'Visible','off');
        drawnow
        set(findobj(gcf,'Tag','ListSelFeats'), 'String', ...
            sort(SelectedFeatPool));
        axes(handles.FeatSelCurve);
    end

3) There is no need to change the name of your data. It works with any name. For example I debugged the previous error by generating a two class problem of 200 patterns (100 per class) and 2000 features estimated on them:

>> x = [0.25+0.1*randn(100,2000); 0.35+0.25*randn(100,2000)];
>> Data = [x [ones(100,1); 2*ones(100,1)]];

That correspond to patternsXfeatures matrix 200 X 2000
and Targets vector 200 X 1

I saved the "Data" variable as "Data.mat" in the [PatTargMatrices] folder and I loaded it with the GUI and I pressed run.

I don't have the linux version of Matlab and I don't know the differences. I don't think that there is any.

BR,
Dimitrios

29 Dec 2009 Feature Selection using Matlab Select the subset of features that maximizes Correct Classification Rate. Author: Dimitrios Ververidis

hi toto11,

1. Which coefficients ? Do you mean those in ReliefF function ? If you mean them, cross-correlation was not exploited.

2. Yes, you can use GA algorithm for feature selection:
       a) add your function GenetAlgo.m in DEMO.m (similarly as ReliefF.m), e.g.
%=============================================

  elseif strcmp(FSSettings.FSMethod,'ReliefF')
       [FeatureWeightsOrdered, FeaturesIndexOrdered, ...
            handles.OptimumFeatureSet] = ReliefF(handles.file,...
                    FSSettings,handles);
   elseif strcmp(FSSettings.FSMethod,'GenetAlgo')
             [FeatureWeightsOrdered, FeaturesIndexOrdered, ...
            handles.OptimumFeatureSet] = GenetAlgo(handles.file,
                    FSSettings,handles);
%=================================================

Do not forget to add 'GenetAlgo' as a string option in the menu of figure. The default is 'SFS'.

Structure FSSettings.YourSettings allows the use of any variables for GA (mutation vars etc.).

NOTE: If you have managed to add it, please send it to me, I will acknowledge you (is there any more formal name than toto11?)

17 Dec 2009 Feature Selection using Matlab Select the subset of features that maximizes Correct Classification Rate. Author: Dimitrios Ververidis

User can select between SFS and SFFS. See menu options. They are not combined.

They both belong to the general forward selection function. SFS is actually a part of SFFS.

With this move I avoided writing the same code twice.

Comments and Ratings on Dimitrios' Files View all
Updated File Comment by Comments Rating
09 Jan 2012 Feature Selection using Matlab Select the subset of features that maximizes Correct Classification Rate. Author: Dimitrios Ververidis Ververidis, Dimitrios

Go to options and make confidence interval smaller. This will increase the number of cross-validation repetitions, thus execution time gets longer. The features selected will be almost identical per run. This is due to the fact that cross-validation involves a random selection of training and testing set.

09 Jan 2012 Feature Selection using Matlab Select the subset of features that maximizes Correct Classification Rate. Author: Dimitrios Ververidis Patrick

Dear all,
I am new to feature selection topic. I have found that this program is useful for my data. However each time i run the program, it ended up with different answers/different features. So could anybody tell me how to choose the best features for my data.

31 Dec 2011 Feature Selection using Matlab Select the subset of features that maximizes Correct Classification Rate. Author: Dimitrios Ververidis Taher, Ahmad
12 Nov 2011 Feature Selection using Matlab Select the subset of features that maximizes Correct Classification Rate. Author: Dimitrios Ververidis belal

hello all,

I have the same problem of tabzim, that when I use the following code it returns just one feature>> could you help me if you solve your problem??

cc = cvpartition(y,'k',10);
opts = statset('display','iter');
[fs,history] = sequentialfs( @fc,X,y,'cv',cc,'direction','backward','options',opts)%,'nfeatures',5)

function [sm]=fc(Xtrain,Ytrain,Xtest,Ytest)
yy=svmclassify(svmtrain(Xtrain,Ytrain),Xtest);
sm=sum(~strcmp(Ytest,yy))
-----

so please help>>

07 Sep 2011 Feature Selection using Matlab Select the subset of features that maximizes Correct Classification Rate. Author: Dimitrios Ververidis Ahn, Sangtae

I have an error as below
What shall I do ?

-----------------------

??? Error using ==> eval
Undefined function or variable 'data'.

Error in ==> DataLoadAndPreprocess at 26
[NPatterns, KInitialFeatures] = eval(['size(' DatasetToUse ')']);

Error in ==> DEMO>OpenDataFile_ClickedCallback at 64
    [Patterns, Targets] = DataLoadAndPreprocess(handles.file);

Error in ==> gui_mainfcn at 96
        feval(varargin{:});

Error in ==> DEMO at 19
    gui_mainfcn(gui_State, varargin{:});
 
??? Error while evaluating uipushtool ClickedCallback

Top Tags Applied by Dimitrios
demo, gui, image processing, signal processing, feature selection
Files Tagged by Dimitrios View all
Updated   File Tags Downloads
(last 30 days)
Comments Rating
24 Feb 2011 Information loss of the Mahalanobis distance in high dimensions: Matlab implementation Information loss estimation to set a lower limit on classification rate. Author: Dimitrios Ververidis pattern recognition, gaussian methods, feature selection, information loss, high dimensionality p... 11 1
29 Aug 2010 Screenshot Feature Selection using Matlab Select the subset of features that maximizes Correct Classification Rate. Author: Dimitrios Ververidis demo, gui, signal processing, image processing, modeling 146 27
  • 3.44444
3.4 | 10 ratings
04 May 2009 Screenshot Gaussian Mixture Modeling GUI (GMM DEMO) GUI for an Expectation-Maximization algorithm (EM) variant (Split-EM-Discriminant) Author: Dimitrios Ververidis demo, mathematics, image processing, gui, optimization, signal processing 33 3
  • 4.0
4.0 | 1 rating

Contact us at files@mathworks.com