## how does Wenergy for 1-D wavelet decomposition works???

### afef (view profile)

on 21 Jul 2017
Latest activity Commented on by Leandro Robaina Arla

on 8 Feb 2019

### Wayne King (view profile)

Hi , i read the matlab documentation about the energy for 1-D wavelet decomposition and i want to know how the calculation works exactly??? because the Syntax used is [Ea,Ed] = wenergy(C,L) so here it use the wavelet decomposition vector c and the formula used in theory is Which use the details and approximations coefficients . can anyone help me to understand please??

### Wayne King (view profile)

on 10 Aug 2017

Hi Alef, the Ed output gives the percentage of energy captured by the detail (wavelet) coefficients at each level, while the Ea output is the coarsest scale (final-level) scaling coefficient energy (again as a percentage).
% 4 levels here
[C,L] = wavedec(noisbump,4,'sym4');
[Ea,Ed] = wenergy(C,L);
Ed is 1-by-4, the percent energy captured by the wavelet coefficients from the finest scale to coarsest scale.
Ea is a scalar representing the final-scale scaling coefficient energy.

#### 1 Comment

Leandro Robaina Arla

### Leandro Robaina Arla (view profile)

on 8 Feb 2019
Hi, i don´t understand completely.