2.11.2.5 idwt(Pro)

Menu Information

Analysis: Signal Processing: Wavelet: Reconstruction

Brief Information

Reconstruct a signal from its coefficients

Additional Information

This feature is for OriginPro only.

Command Line Usage

1. idwt ca:=Col(1) cd:=Col(2); 
2. idwt ca:=Col(1) cd:=Col(2) ext:=z; 
3. idwt ca:=Col(1) cd:=Col(2) type:=db3; 
4. idwt ca:=Col(1) cd:=Col(2) ox:=Col(3); //coefficients in Column 1 and 2; save the result to Column 3

X-Function Execution Options

Please refer to the page for additional option switches when accessing the x-function from script

Variables

Description

idwt reconstructs a signal from its approximation coefficients and detail coefficients.

To construct the signal correctly, the wavelet type and the boundary should be the same with the options chosen for the decomposition that has produced the coefficients.

Examples

• To reconstruct a signal from its approximation coefficients and detail coefficients saved in Column 1 and 2 of the active sheet using DB4 wavelet and periodic as the extension mode, use the Command Window:

idwt ca:=Col(1) cd:=Col(2) type:=1

• To perform idwt using a pre-saved analysis theme called MyTheme, use the Command Window:

idwt -t "MyTheme"

• Code Sample

// Wavelet decomposition and reconstruction with two different wavelet types
//Create a new workbook and import sample data
newbook  name:="Wavelet Demo" sheet:=1;
fname$=system.path.program$ + "Samples\Signal Processing\Step Signal With Random Noise.dat";
impasc;

//Multi-level wavelet decomposition using two wavelet types
mdwt ix:=col(2) type:=haar level:=3 rd:=[<input>]"Haar";
mdwt ix:=1!col(2) type:=db7 level:=3 rd:=[<input>]"DB7";
//Reconstruction
idwt ca:=2!1 cd:=2!2 type:=haar;
idwt ca:=2!5 cd:=2!3 type:=haar;
idwt ca:=2!6 cd:=2!4 type:=haar;
idwt ca:=3!1 cd:=3!2 type:=db2;
idwt ca:=3!5 cd:=3!3 type:=db2;
idwt ca:=3!6 cd:=3!4 type:=db2;

//Report
newsheet name:="report" labels:="|Haar|DB7";
wcolwidth irng:=1:3 width:="15";
wrowheight irng:=col(1)[1:5] height:=5;
wcellcolor irng:=col(1)[1:5] color:=color(249, 236, 151);
col(1)[1]$="CA3";
col(1)[2]$="CD3";
col(1)[3]$="CD2";
col(1)[4]$="CD1";
col(1)[5]$="Reconstructed";
//Insert sparklines for coefficients and reconstructed signals
insertSparklines irng:=(2!1:4, 2!7)  name:=0 orng:=col(2)[1];
insertSparklines irng:=(3!1:4, 3!7)  name:=0 orng:=col(3)[1];

window -z; //Maximize window

More Information

For more information, please refer to our User Guide.

• Algorithm
• Reference

Related X-Functions

dwt, dwt2, idwt2

Keywords:wavelet, approximation