Name

cemdc — bivariate Empirical Mode Decomposition, first algorithm

Calling Sequence

   [IMF,NB_ITERATIONS]=cemdc(T,X);
   [IMF,NB_ITERATIONS]=cemdc([],X);
   [IMF,NB_ITERATIONS]=cemdc(T,X,STOP_PARAMETERS,MAX_IMFS,NDIRS);
   [IMF,NB_ITERATIONS]=cemdc(T,X,STOP_PARAMETERS,MAX_IMFS,NDIRS);
   [IMF,NB_ITERATIONS]=cemdc(T,X,STOP_PARAMETERS,MAX_IMFS,NDIRS);
   

Parameters

inputs:

- T:

1xN time instants, sampling times. If T=[], the signal is assumed uniformly sampled.

- X:

analyzed signal, 1xN signal data

- STOP_PARAMETERS:

parameters for the stopping criterion: if scalar the value is used to specify THRESHOLD only. otherwise the vector should be: [THRESHOLD,TOLERANCE]. if STOP_PARAMETERS is unspecified or empty, default values are used: [0.05,0.05]

- MAX_IMFS:

maximum number of IMFs to be extracted. If MAX_IMFS is zero, empty or unspecified, the default behavior is to extract as many IMFs as possible.

- NDIRS:

number of directions used to compute the local mean. If unspecified, the default value is 4. TODO: the actual number of directions (according to [1]) is 2*NDIRS

outputs:

- IMF:

intrinsic mode functions (IMFs) (last line = residual)

- NB_ITERATIONS:

effective number of sifting iterations for each mode

Description

computes bivariate EMD, first algorithm [1] with stopping criterion for sifting similar to the one proposed in [2]:

mean of boolean array {(mean_amplitude)/(envelope_amplitude) > THRESHOLD} < TOLERANCE

References [1] G. Rilling, P. Flandrin, P. Gonçalves and J. M. Lilly., "Bivariate Empirical Mode Decomposition", Signal Processing Letters (submitted)

[2] G. Rilling, P. Flandrin and P. Gonçalves "On Empirical Mode Decomposition and its algorithms", IEEE-EURASIP Workshop on Nonlinear Signal and Image Processing NSIP-03, Grado (I), June 2003

Examples

IMF = CEMDC(T,X);
[IMF,NB_IT] = CEMDC([],X);
IMF = CEMDC(T,X,0.1);
IMF = CEMDC(T,X,[0.1,0.1]);
[IMF,NB_IT] = CEMDC([],X,[],4);
   

See also

cemd_visu, emd_visu, emd, cemdc2_fix, cemdc, cemdc_fix

Authors

H. Nahrstaedt
G. Rilling, last modification: 3.2007
gabriel.rilling@ens-lyon.fr
code based on a student project by T. Boustane and G. Quellec, 11.03.2004
supervised by P. Chainais (ISIMA - LIMOS - Universite Blaise Pascal - Clermont II
email : pchainai@isima.fr).