1028 ISSN: 1693-6930
2. RBF: K X
i
, X
j
= exp−γ|X
i
− X
j
|
2
3. Sigmoid: K X
i
, X
j
= tanhγX
i
· X
j
+ C where K
X
i
, X
j
= φX
i
· φX
j
, kernel function that should be used to substitute the dot product in the feature space is highly dependent on the data.
2.4.2. K-Fold Cross Validation
For classification problems, the performance is measured of a model in terms of its error rate percentage of incorrectly classified instances in the data set. In classification, two data sets
are used: the training set seen data to build the model determine its parameters and the test set unseen data to measure its performance holding the parameters constant. To split data
into training and test set, a k-Fold Cross Validation is used.
K-Fold Cross Validation divides data randomly into k folds subsets of equal size. The k-1 folds are used for training the model, and one fold is used for testing. This process will be
repeated k times so that all folds are used for testing. The overall performance is obtained by computing the average performance on the k test sets. This method effectively uses all the data
for both training and testing. Typically k=5 or k = 10 are used for effective fold sizes [22].
2.4.3. Confusion Matrix
In the field of machine learning, a confusion matrix, is a specific table layout that allows visualization of the performance of an algorithm, typically a supervised learning one [23]. Each
column of the matrix represents the instances in a predicted class, while each row represents the instances in an actual class.As seen on Figure 2, the entries in the confusion matrix have the
following meaning:
Figure 2. Confusion matrix. – a is the number of correct predictions that an instance is negative,
– b is the number of incorrect predictions that an instance is positive, – c is the number of incorrect of predictions that an instance negative, and
– d is the number of correct predictions that an instance is positive.
3. Methodology
In this research, there are several steps to be done. These steps include data collection, feature extraction, data preprocessing, classification, and performance evaluation.
3.1. Data Collection, Feature Extraction, Data Preprocessing
The data set of music files that is used to be classified in the experiment is GTZAN [8]. The data set contains 1000 music files in .wav format. Each file has 30 second long of duration
and is recorded using 22050 Hz sample rate and 16-bit sample size in mono channel. This
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