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EMD Toolbox >> EMD Toolbox > Empirical Mode Decomposition > emd_local

emd_local

("Local" Empirical Mode Decomposition) computes a local version of EMD

Calling Sequence

[imf,ort,nbits] = emd_local(x)
[imf,ort,nbits] = emd_local([],x)
[imf,ort,nbits] = emd_local(t,x)
[imf,ort,nbits] = emd_local([],x,stop)
[imf,ort,nbits] = emd_local(t,x,stop)
[imf,ort,nbits] = emd_local([],x,stop,tst)
[imf,ort,nbits] = emd_local(t,x,stop,tst)

Parameters

inputs:

- x :

analyzed signal (line vector)

- t (optional) :

sampling times (line vector) (default : 1:length(x))

- stop (optional) :

threshold, threshold2 and tolerance (optional) for sifting stopping criterion default : [0.05,0.5,0.05]

- tst (optional) :

if equals to 1 shows sifting steps with pause if equals to 2 no pause

outputs:

- imf :

intrinsic mode functions (last line = residual)

- ort :

index of orthogonality

- nbits :

number of iterations for each mode

Description

stopping criterion for sifting : at each point : mean amplitude < threshold2*envelope amplitude & mean of boolean array ((mean amplitude)/(envelope amplitude) > threshold) < tolerance & |#zeros-#extrema|<=1

Examples

s = rand(1,512,'normal');
imf = emd_local(s);
emd_visu(s,imf);

See also

Authors

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