Keywords - Function groups - @ A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Group: Mathematical Functions
Topic: Fourier and Wavelet transforms
See also: dwt fwt invfwt fwtin invfwtin fwtinshift fwt2 invfwt2

Function: invdwt
Description: invdwt computes the inverse Discrete Wavelet Transformation of a vector.

Link:
Usage: x = invdwt (y, l, h)
Input:
y n x 1 vector, coefficients of a wavelet transform using dwt, where n has a power of 2
l integer, number of father wavelet coefficients
h m x 1 vector, wavelet basis
Output:
x n x 1 vector,

Note:

Example:



library ("wavelet")

x = (0:1023)/1023

d = dwt (x, 4, daubechies4)

d = d.*(abs(d)>0.1)

y = invdwt(d, 4, daubechies4)

x~y

Result:



Contents of _tmp

[   1,]        0  0.0049578 

[   2,]  0.00097752 -0.0018849 

[   3,]  0.001955  0.001955 

[   4,]  0.0029326  0.0029326 

[   5,]  0.0039101  0.0039101 

[   6,]  0.0048876  0.0048876 

...

[1019,]  0.99511   1.0014 

[1020,]  0.99609   1.0039 

[1021,]  0.99707  0.98087 

[1022,]  0.99804  0.96467 

[1023,]  0.99902   1.0011 

[1024,]        1   1.0235 


Group: Mathematical Functions
Topic: Fourier and Wavelet transforms
See also: dwt fwt invfwt fwtin invfwtin fwtinshift fwt2 invfwt2

Keywords - Function groups - @ A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

(C) MD*TECH Method and Data Technologies, 21.9.2000