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function [msg,nfft,Fs,window,noverlap,p,dflag] = mypsdchk(P,x,y) %输入参数说明：数组P可为0-7个数的数组参数；y是可选项，若给出，必须与x的长度相同 % x必须是一个数值向量 % 输出参数说明: msg-错误信息,没有错误为[]；nfft - fft变换的指定长度 % Fs-抽样频率；window-窗函数数组；noverlap - overlap of sections, in samples % p-confidence interval, [] if none desired；dflag - detrending flag, 'linear' 'mean' or 'none' msg = []; %信息提示数组初始化 if length(P) == 0 %输入数组为0的情况下，对输出参数赋值 % psd(x) nfft = min(length(x),256); window = hanning(nfft); noverlap = 0; Fs = 2; p = []; dflag = 'none'; elseif length(P) == 1 %输入数组为1的情况下，对输出参数赋值 if isempty(P{1}), dflag = 'none'; nfft = min(length(x),256); elseif isstr(P{1}), dflag = P{1}; nfft = min(length(x),256); else dflag = 'none'; nfft = P{1}; end Fs = 2; window = hanning(nfft); noverlap = 0; p = []; elseif length(P) == 2 %输入数组为2的情况下，对输出参数赋值 if isempty(P{1}), nfft = min(length(x),256); else nfft=P{1}; end if isempty(P{2}), dflag = 'none'; Fs = 2; elseif isstr(P{2}), dflag = P{2}; Fs = 2; else dflag = 'none'; Fs = P{2}; end window = hanning(nfft); noverlap = 0; p = []; elseif length(P) == 3 %输入数组为3的情况下，对输出参数赋值 if isempty(P{1}), nfft = min(length(x),256); else nfft=P{1}; end if isempty(P{2}), Fs = 2; else Fs = P{2}; end if isstr(P{3}) dflag = P{3}; window = hanning(nfft); else dflag = 'none'; window = P{3}; if length(window) == 1, window = hanning(window); end if isempty(window), window = hanning(nfft); end end noverlap = 0; p = []; elseif length(P) == 4 %输入数组为4的情况下，对输出参数赋值 if isempty(P{1}), nfft = min(length(x),256); else nfft=P{1}; end if isempty(P{2}), Fs = 2; else Fs = P{2}; end window = P{3}; if length(window) == 1, window = hanning(window); end if isempty(window), window = hanning(nfft); end if isstr(P{4}) dflag = P{4}; noverlap = 0; else dflag = 'none'; if isempty(P{4}), noverlap = 0; else noverlap = P{4}; end end p = []; elseif length(P) == 5 %输入数组为5的情况下，对输出参数赋值 if isempty(P{1}), nfft = min(length(x),256); else nfft=P{1}; end if isempty(P{2}), Fs = 2; else Fs = P{2}; end window = P{3}; if length(window) == 1, window = hanning(window); end if isempty(window), window = hanning(nfft); end if isempty(P{4}), noverlap = 0; else noverlap = P{4}; end if isstr(P{5}) dflag = P{5}; p = []; else dflag = 'none'; if isempty(P{5}), p = .95; else p = P{5}; end end elseif length(P) == 6 %输入数组为6的情况下，对输出参数赋值 if isempty(P{1}), nfft = min(length(x),256); else nfft=P{1}; end if isempty(P{2}), Fs = 2; else Fs = P{2}; end window = P{3}; if length(window) == 1, window = hanning(window); end if isempty(window), window = hanning(nfft); end if isempty(P{4}), noverlap = 0; else noverlap = P{4}; end if isempty(P{5}), p = .95; else p = P{5}; end if isstr(P{6}) dflag = P{6}; else msg = 'DFLAG parameter must be a string.'; return end end % 进行错误检测 if (nfft<length(window)), msg = 'Requires window''s length to be no greater than the FFT length.'; end if (noverlap >= length(window)), msg = 'Requires NOVERLAP to be strictly less than the window length.'; end if (nfft ~= abs(round(nfft)))|(noverlap ~= abs(round(noverlap))), msg = 'Requires positive integer values for NFFT and NOVERLAP.'; end if ~isempty(p), if (prod(size(p))>1)|(p(1,1)>1)|(p(1,1)<0), msg = 'Requires confidence parameter to be a scalar between 0 and 1.'; end end if min(size(x))~=1 | ~isnumeric(x) | length(size(x))>2 msg = 'Requires vector (either row or column) input.'; end if (nargin>2) & ( (min(size(y))~=1) | ~isnumeric(y) | length(size(y))>2 ) msg = 'Requires vector (either row or column) input.'; end if (nargin>2) & (length(x)~=length(y)) msg = 'Requires X and Y be the same length.'; end dflag = lower(dflag); if strncmp(dflag,'none',1) dflag = 'none'; elseif strncmp(dflag,'linear',1) dflag = 'linear'; elseif strncmp(dflag,'mean',1) dflag = 'mean'; else msg = 'DFLAG must be ''linear'', ''mean'', or ''none''.'; end