java 频域滤波算法

以下是Java中频域滤波的算法示例：

import org.apache.commons.math3.transform.DftNormalization org.apache.commons.math3.transform.FastFourierTransformer;
import org.apache.math3.transform.TransformType;

public class FrequencyDomainFilter {
    public static void main(String[] args) {
        // 输入信号
        double[] inputSignal = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};

        // 进行快速傅里叶变换
        FastFourierTransformer transformer = new FastFourierTransformer(DftNormalization.STANDARD);
        Complex[] frequencyDomain = transformer.transform(inputSignal, TransformType.FORWARD);

        // 频域滤波，将不需要的频率置零
        int cutoffFrequency = 3; // 截止频率
        for (int i = 0; i < frequencyDomain.length; i++) {
            if (i > cutoffFrequency && i < frequencyDomain.length - cutoffFrequency) {
                frequencyDomain[i] = Complex.ZERO;
            }
        }

        // 进行反傅里叶变换，得到滤波后的时域信号
        Complex[] filteredSignal = transformer.transform(frequencyDomain, TransformType.INVERSE);

        // 输出滤波后的时域信号
        for (Complex value : filteredSignal) {
            System.out.println(value.getReal());
        }
    }
}