Feature selection using a sinusoidal sequence combined with mutual information

Data classification is the most common task in machine learning, and feature selection is the key step in the classification task. Common feature selection methods mainly analyze the maximum correlation and minimum redundancy between feature factors and tags while ignoring the impact of the number of key features, which will inevitably lead to waste in subsequent classification training. To solve this problem, a feature selection algorithm (SSMI) based on the combination of sinusoidal sequences and mutual information is proposed. First, the mutual information between each feature and tag is calculated, and the interference information in high-dimensional data is removed according to the mutual information value. Second, a sine function is constructed, and sine ordering is carried out according to the mutual information value and feature mean value between different categories of the same feature. By adjusting the period and phase value of the sequence, the feature set with the largest difference is found, and the subset of key features is obtained. Finally, three machine learning classifiers (KNN, RF, SVM) are used to classify key feature subsets, and several feature selection algorithms (JMI, mRMR, CMIM, SFS, etc.) are compared to verify the advantages and disadvantages of different algorithms. Compared with other feature selection methods, the SSMI algorithm obtains the least number of key features, with an average reduction of 15 features. The average classification accuracy has been improved by 3% on the KNN classifier. On the HBV and SDHR datasets, the SSMI algorithm achieved classification accuracy of 81.26% and 83.12%, with sensitivity and specificity results of 76.28%, 87.39% and 68.14%, 86.11%, respectively. This shows that the SSMI algorithm can achieve higher classification accuracy with a smaller feature subset.