Training weka models in matlab: how to evaluate? Mssing some model type? - matlab

Question

despite using weka I have models like libSVM and RseslibKnn, when I call them in Matlab it can't find them
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and I noticed that actually they are not part of the models of the directories "classifiers".
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I know how to crossvalidate a generic model but I can't use the simple validation with determinated training and test set. Here the code I'm using:
% memorize current folder and change folder
base_folder = cd;
cd 'C:\Program Files'
% adding weka in the java folder
javaaddpath("weka-3-8-4/weka.jar");
% loading arff training set
l = javaObject("weka.core.converters.ArffLoader");
l.setFile(javaObject("java.io.File","weka-3-8-4/data/weka_BEST_train_ESS.arff"));
tr = l.getDataSet;
tr.toString;
% building classfiers
c = javaObject("weka.classifiers.functions.MultilayerPerceptron");
tr.setClassIndex(tr.numAttributes - 1);
c.buildClassifier(tr);
c.toString;
% loading arff test set
l = javaObject("weka.core.converters.ArffLoader");
l.setFile(javaObject("java.io.File","weka-3-8-4/data/weka_BEST_test_ESS.arff"));
ts = l.getDataSet;
ts.toString;
% validation
e = javaObject("weka.classifiers.Evaluation", tr);
e.evaluateModel(c, ts); %?????????????????????????????????????????????????????????????????????
e.toSummaryString;
% going back to the current folder
cd (base_folder)

Answer 1

Answering to the first question:
libSVM and RseslibKnn are models available in separate Weka packages that need to be additionally installed in Weka. To install the packages run Weka package manager (menu Tools -> Package Manager in Weka GUI Chooser) and install LibSVM and Rseslib packages. The packages with their java jars are installed in the wekafiles directory. On Windows it is C:\Users\ <username>\wekafiles\packages by default.
I don't know Matlab but I guess that to use models from extra Weka packages you need to add also the package jar files to Matlab javapath after installing the packages in Weka:
javaaddpath("C:\Users\ <username>\wekafiles\packages\Rseslib\rseslib.jar");
javaaddpath("C:\Users\ <username>\wekafiles\packages\LibSVM\LibSVM.jar");
Alternatively, you can download the libraries directly from the web sites of the package providers, unpack them and add jars to Matlab javapath:
http://rseslib.mimuw.edu.pl/download.html
https://www.csie.ntu.edu.tw/~cjlin/libsvm/