如何将.arff格式文件加载到matlab

是否有任何包加载.arff格式文件到matlab？.arff格式在Weka中用于运行机器学习算法.

由于Weka是一个Java库,您可以直接使用它公开的API来读取ARFF文件:

%## paths
WEKA_HOME = 'C:\Program Files\Weka-3-7';
javaaddpath([WEKA_HOME '\weka.jar']);
fName = [WEKA_HOME '\data\iris.arff'];

%## read file
loader = weka.core.converters.ArffLoader();
loader.setFile( java.io.File(fName) );
D = loader.getDataSet();
D.setClassIndex( D.numAttributes()-1 );

%## dataset
relationName = char(D.relationName);
numAttr = D.numAttributes;
numInst = D.numInstances;

%## attributes
%# attribute names
attributeNames = arrayfun(@(k) char(D.attribute(k).name), 0:numAttr-1, 'Uni',false);

%# attribute types
types = {'numeric' 'nominal' 'string' 'date' 'relational'};
attributeTypes = arrayfun(@(k) D.attribute(k-1).type, 1:numAttr);
attributeTypes = types(attributeTypes+1);

%# nominal attribute values
nominalValues = cell(numAttr,1);
for i=1:numAttr
    if strcmpi(attributeTypes{i},'nominal')
        nominalValues{i} = arrayfun(@(k) char(D.attribute(i-1).value(k-1)), 1:D.attribute(i-1).numValues, 'Uni',false);
    end
end

%## instances
data = zeros(numInst,numAttr);
for i=1:numAttr
    data(:,i) = D.attributeToDoubleArray(i-1);
end

%## visualize data
parallelcoords(data(:,1:end-1), ...
    'Group',nominalValues{end}(data(:,end)+1), ...
    'Labels',attributeNames(1:end-1))
title(relationName)

您甚至可以直接使用MATLAB的功能.一个例子:

%## classification
classifier = weka.classifiers.trees.J48();
classifier.buildClassifier( D );
fprintf('Classifier: %s %s\n%s', ...
    char(classifier.getClass().getName()), ...
    char(weka.core.Utils.joinOptions(classifier.getOptions())), ...
    char(classifier.toString()) )

输出C4.5决策树:

Classifier: weka.classifiers.trees.J48 -C 0.25 -M 2
J48 pruned tree
------------------

petalwidth <= 0.6: Iris-setosa (50.0)
petalwidth > 0.6
|   petalwidth <= 1.7
|   |   petallength <= 4.9: Iris-versicolor (48.0/1.0)
|   |   petallength > 4.9
|   |   |   petalwidth <= 1.5: Iris-virginica (3.0)
|   |   |   petalwidth > 1.5: Iris-versicolor (3.0/1.0)
|   petalwidth > 1.7: Iris-virginica (46.0/1.0)

Number of Leaves  :     5

Size of the tree :  9