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输入： EEG_file: EEG Signal File welch_len: the length you want to welch seg_len: length of each segment Fs: sampling rate |
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输出： Wel_psd: the Welch estimate of PSD（1） Initialization: over_len = seg_len/2;//Length of overlap between the successive segments（2） Data are read from EEG_file and stored into the arrary welch[N];（3） Calculate how many segments:N_segs.（4） for index in range (0, seg_len)（5） Create Hamming window win[一世];（6）你+ = Win [index] * win [index]; //计算累计值你;（7） index++;（8） end for（9） for seg_start in range (1, x_len-seg_len + 1)（10） seg_end = seg_start + seg_len −1; //seg_start and seg_end is start point and end point of each data segment, respectively.（11） apply Hamming window to the data of welch [N]在[seg_start，seg_end]之间;（12） Do FFT for windowed data. The result is stored in variable fft_x;（13） Calculating the square of the amplitude of the fft_x. The result is stored in variable pgram;（14） Summate power spectra Pxy + = pgram;（15） start_seg + = seg_len-overlap;（16） end for（17） Wel_psd = Pxy/(N_ffts×fs× 你）; |
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