wrcoef (Wavelet Toolbox)

Reconstruct single branch from 1-D wavelet coefficients

Syntax

X = wrcoef('type',C,L,'wname',N)
X = wrcoef('type',C,L,Lo_R,Hi_R,N)
X = wrcoef('type',C,L,'wname')
X = wrcoef('type',C,L,Lo_R,Hi_R)

Description

wrcoef reconstructs the coefficients of a one-dimensional signal, given a wavelet decomposition structure (C and L) and either a specified wavelet ('wname', see wfilters for more information) or specified reconstruction filters (Lo_R and Hi_R).

X = wrcoef('type',C,L,'wname',N) computes the vector of reconstructed coefficients, based on the wavelet decomposition structure [C,L] (see wavedec for more information), at level N. 'wname' is a string containing the wavelet name.

Argument 'type' determines whether approximation ('type' = 'a') or detail ('type' = 'd') coefficients are reconstructed. When 'type' = 'a', N is allowed to be 0; otherwise, a strictly positive number N is required. Level N must be an integer such that N length(L)-2.

X = wrcoef('type',C,L,Lo_R,Hi_R,N) computes coefficients as above, given the reconstruction filters you specify.

X = wrcoef('type',C,L,'wname') and X = wrcoef('type',C,L,Lo_R,Hi_R) reconstruct coefficients of maximum level N = length(L)-2.

Examples

% The current extension mode is zero-padding (see dwtmode).

% Load a one-dimensional signal. 
load sumsin; s = sumsin; 

% Perform decomposition at level 5 of s using sym4. 
[c,l] = wavedec(s,5,'sym4');

% Reconstruct approximation at level 5, 
% from the wavelet decomposition structure [c,l].
a5 = wrcoef('a',c,l,'sym4',5);

% Using some plotting commands,
% the following figure is generated.

See Also
appcoef, detcoef, wavedec

wpviewcf wrcoef2