¡¡ ¡¡ ¡¡ HHT MATLAB program The current MATLAB program of HHT includes the following modules: 1) eemd.m. The module that performs EMD/EEMD; 2) ifndq.m. The module that calculates an instantaneous frequency for a given IMF; and 3) extrema.m. A supporting module that is used by the previous two modules. ¡¡ 4) significance.m This is used to obtain the "percenta" line based on Wu and Huang (2004). ¡¡ 5) dist_value.m This is a utility program being called by "significance.m". ¡¡ The modules of the program are suggested to be in a folder (for example folder ¡°EEMD¡±) under the MATLAB ¡°toolbox¡± folder (C:\MATLAB6p5\toolbox\EEMD). By adding the MATLAB path to that directory, the programs are ready to be used. Some interface related information is given in each program. The ¡°help¡± command can be used to get these information. The above programs are the preliminary version of an HHT software. In future, more modules that provide more features such statistical test, calculation of marginal spectrum, and visualization in time-frequency-energy domain, will be added.