求助：关于EMD的toimage.m
EMD分解后想得到信号的频谱信息运行Grilling 提供的程序toimage.m时，builtin报错，说accumarray有问题
是怎么回事
回复 #39 jingrenzhi 的帖子
对应8楼的程序
t=1:500;
t=t*1/400;
x1=sin(2*pi*20*t);
x2=0.4*sin(2*pi*40*t+140);
z=x1+x2
plot(t,z)
y= linspace(1,2,500);%添加趋势项
z=z+y
imf=emd(z);
emd_visu(z,1:length(z),imf)
=hhspectrum(imf);
=toimage(A,f);
disp_hhs(im);
colormap(flipud(gray))
[ 本帖最后由 zhangnan3509 于 2007-6-1 15:35 编辑 ]
就是这个http://forum.vibunion.com/forum/viewthread.php?tid=44797&extra=page%3D1%26amp%3Bfilter%3Dtype%26amp%3Btypeid%3D187&page=3 没有得到zhangnan3509 相应的效果阿
指点下 toimage.m里有句：
im = accumarray(,A(:),);
就是这个accumarray函数的问题
回复 #4 yao_zq 的帖子
有个帖子讨论过accumarray的问题，你可以搜索一下。另外这个函数是新版的程序里才有的。 工具箱里有啊
我再贴下
%TOIMAGEtransforms a spectrum made of 1D functions in an 2D image
%
% = TOIMAGE(A,f,t,splx,sply) transforms a spectrum made
% of 1D functions (e.g., output of "hhspectrum") in an 2D image
%
% inputs : - A : amplitudes of modes (1 mode per row of A)
% - f : instantaneous frequencies
% - t : time instants
% - splx : number of columns of the output im (time resolution).
% If different from length(t), works only for uniform
% sampling.
% - sply : number of rows of the output im (frequency resolution).
% outputs :- im : 2D image of the spectrum
% - tt : time instants in the image
% - ff : centers of the frequency bins
%
% Examples : = toimage(A,f); = toimage(A,f,t); = toimage(A,f,sply);
% = toimage(A,f,splx,sply); = toimage(A,f,t,splx,sply);
%
%
% See also
%emd, hhspectrum, disp_hhs
%
% G. Rilling, last modification 3.2007
% gabriel.rilling@ens-lyon.fr
function = toimage(A,f,varargin)
DEFSPL = 400;
error(nargchk(2,5,nargin));
switch nargin
case 2
t = 1:size(A,2);
sply = DEFSPL;
splx = length(t);
case 3
if isscalar(varargin{1})
t = 1:size(A,2);
splx = length(t);
sply = varargin{1};
else
t = varargin{1};
splx = length(t);
sply = DEFSPL;
end
case 4
if isscalar(varargin{1})
t = 1:size(A,2);
sply = varargin{1};
splx = varargin{2};
else
t = varargin{1};
sply = varargin{2};
splx = length(t);
end
case 5
t = varargin{1};
splx = varargin{2};
sply = varargin{3};
end
if isvector(A)
A = A(:)';
f = f(:)';
end
if issparse(A) || ~isreal(A) || length(size(A)) > 2
error('A argument must be a real matrix')
end
if issparse(f) || ~isreal(f) || length(size(f)) > 2
error('f argument must be a real matrix')
end
if any(size(f)~=size(A))
error('A and f matrices must have the same size')
end
if issparse(t) || ~isreal(t) || ~isvector(t) || length(t)~=size(A,2)
error('t argument must be a vector and its length must be the number of columns in A and f inputs')
end
if ~isscalar(splx) || ~isreal(splx) || splx ~= floor(splx) || splx <= 0
error('splx argument must be a positive integer')
end
if ~isscalar(sply) || ~isreal(sply) || sply ~= floor(sply) || sply <= 0
error('splx argument must be a positive integer')
end
if any(diff(diff(t))) && splx ~= length(t)
warning('toimage:nonuniformtimeinsants','When splx differs from length(t), the function only works for equally spaced time instants. You may consider reformating your data (using e.g. interpolation) before using toimage.')
end
f = min(f,0.5);
f = max(f,0);
indf = round(2*f*(sply-1)+1);
indt = repmat(round(linspace(1,length(t),splx)),size(A,1),1);
im = accumarray(,A(:),);
indt = indt(1,:);
tt = t(indt);
ff = (0:sply-1)*0.5/sply+1/(4*sply);
end 不好意思
根错贴子了
是回复另外一个的:@L
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