[心得] 新手問一個函式的問題已回收

看板MATLAB作者jiahunglin (haha)時間14年前 (2011/08/15 18:03)推噓1(1推 0噓 2→)

留言3則, 3人參與討論串1/1

我正要做一個氣溫的EMD(經驗模態分解) 從中央大學下載了一個eemd.m 以前從沒碰過matlab，正在看書自學有個可能在各位眼中很蠢的問題想請教大家現有一筆1*96的氣溫資料temp01.txt 內容是某測站連續96筆的月均溫以下是函式eemd.m % This is an EMD/EEMD program % % function allmode=eemd(Y,Nstd,NE) % % INPUT: % Y: Inputted data; % Nstd: ratio of the standard deviation of the added noise and that of Y; % NE: Ensemble number for the EEMD % OUTPUT: % A matrix of N*(m+1) matrix, where N is the length of the input % data Y, and m=fix(log2(N))-1. Column 1 is the original data, columns 2, 3, ... % m are the IMFs from high to low frequency, and comlumn (m+1) is the % residual (over all trend). % % NOTE: % It should be noted that when Nstd is set to zero and NE is set to 1, the % program degenerates to a EMD program. % % References can be found in the "Reference" section. % % The code is prepared by Zhaohua Wu. For questions, please read the "Q&A" section or % contact % zwu@fsu.edu % function allmode=eemd(Y,Nstd,NE) xsize=length(Y); dd=1:1:xsize; Ystd=std(Y); Y=Y/Ystd; TNM=fix(log2(xsize))-1; TNM2=TNM+2; for kk=1:1:TNM2, for ii=1:1:xsize, allmode(ii,kk)=0.0; end end for iii=1:1:NE, for i=1:xsize, temp=randn(1,1)*Nstd; X1(i)=Y(i)+temp; end for jj=1:1:xsize, mode(jj,1) = Y(jj); end xorigin = X1; xend = xorigin; nmode = 1; while nmode <= TNM, xstart = xend; iter = 1; while iter<=10, [spmax, spmin, flag]=extrema(xstart); upper= spline(spmax(:,1),spmax(:,2),dd); lower= spline(spmin(:,1),spmin(:,2),dd); mean_ul = (upper + lower)/2; xstart = xstart - mean_ul; iter = iter +1; end xend = xend - xstart; nmode=nmode+1; for jj=1:1:xsize, mode(jj,nmode) = xstart(jj); end end for jj=1:1:xsize, mode(jj,nmode+1)=xend(jj); end allmode=allmode+mode; end allmode=allmode/NE; allmode=allmode*Ystd; 在這個涵式中要輸入的引數為Y,Nstd,NE Y為氣溫資料，在note中設定Nstd為0,NE為1 我的輸入如下 >> load temp01.txt >> Y=temp01(:,1) >> Nstd=0 Nstd = 0 >> NE=1 NE = 1 接著試著執行都是錯誤 >> eemd ??? Input argument "Y" is undefined. Error in ==> eemd at 27 xsize=length(Y); >> eemd(Y,Nstd,NE) ??? Undefined function or method 'extrema' for input arguments of type 'double'. Error in ==> eemd at 59 [spmax, spmin, flag]=extrema(xstart); >> eemd(temp01(:,1),0,1) ??? Undefined function or method 'extrema' for input arguments of type 'double'. Error in ==> eemd at 59 [spmax, spmin, flag]=extrema(xstart); 有高手可以提點我一下那裏有錯嗎? 從書中實在找不到解決方法感恩 -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 218.167.194.15