Abstract
A MATLAB-based computer code has been developed for the simultaneous wavelet analysis and filtering of several environmental time series, particularly focused on the analyses of cave monitoring data. The continuous wavelet transform, the discrete wavelet transform and the discrete wavelet packet transform have been implemented to provide a fast and precise time–period examination of the time series at different period bands. Moreover, statistic methods to examine the relation between two signals have been included. Finally, the entropy of curves and splines based methods have also been developed for segmenting and modeling the analyzed time series. All these methods together provide a user-friendly and fast program for the environmental signal analysis, with useful, practical and understandable results.
Program title: EnvironmentalWaveletTool
Catalogue identifier: AETL_v1_0
Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AETL_v1_0.html
Program obtainable from: CPC Program Library, Queen’s University, Belfast, N. Ireland
Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html
No. of lines in distributed program, including test data, etc.: 43 223
No. of bytes in distributed program, including test data, etc.: 9 835 648
Distribution format: tar.gz
Programming language: MATLAB (MathWorks Inc.) version 7.8.0.347 (R2009a) or higher. Wavelet Toolbox is required.
Computer: Developed on a MacBook Pro. Tested on Mac and PC. No computer-specific optimization was performed.
Operating system: Any supporting MATLAB (MathWorks Inc.) v7.8.0.347 (R2009a) or higher. Tested on Mac OS X 10.6.8 and Vista.
Classification: 13.
Nature of problem:
Wavelet analysis has not been widely employed in environmental data since an easy program to specifically process this kind of time series does not exist. In recent years, wavelet analysis has been applied to some situations focused on specific problems and signals, but the extension of these wavelet-based methods to other particular problems is not always a trivial work. In fact, the application to other different situations requires a basic knowledge of the wavelet analysis and their implementation using some standard toolboxes, packages or libraries, such as the MathWorks’ Wavelet Toolbox for MATLAB.
Solution method:
The developed MATLAB-based computer code provides a user-friendly and fast program for the simultaneous wavelet analysis and filtering of several environmental time series. The continuous wavelet transform, the discrete wavelet transform and the discrete wavelet packet transform have been implemented to proffer a fast and precise time–period examination of the time series at different period (or frequency) bands. Moreover, other useful tools have been specifically included for the analysis of the environmental time series obtained from cave monitoring, such as filtering, cross-correlation, entropy of curves or splines analyses.
Additional comments:
A README file giving the names and a brief description of all the files that make up the package and clear instructions on the installation and execution of the program is included in the distribution package. Also included are Sample input files.
Running time:
Interactive.
Keywords: Environmental time series, Continuous wavelet transform, Discrete wavelet transform, Discrete wavelet packet transform, Segmentation, MATLAB program
