---

costshannon Class Reference

The costshannon class extends the abstract class costbase with a concrete implementation of the costCalc function that implements the a modified version of the Shannon entropy function as a cost function. More...

#include <costshannon.h>

Inheritance diagram for costshannon::

List of all members.

Public Methods
	costshannon (packnode< double > *node)
	Calculate a modified version of the the Shannon entropy cost function for the wavelet packet tree, filling in the cost value at each node. More...
Protected Methods
double	costCalc (packnode< double > *node)
	An implementation of a modified version of the Shannon entropy function as a wavelet packet cost function. More...

---

Detailed Description

The costshannon class extends the abstract class costbase with a concrete implementation of the costCalc function that implements the a modified version of the Shannon entropy function as a cost function.

Author:

Ian Kaplan

Definition at line 50 of file costshannon.h.

---

Constructor & Destructor Documentation

costshannon::costshannon ( packnode< double > * node ) [inline]

Calculate a modified version of the the Shannon entropy cost function for the wavelet packet tree, filling in the cost value at each node. Definition at line 60 of file costshannon.h. { traverse( node ); }

---

Member Function Documentation

double costshannon::costCalc ( packnode< double > * node ) [protected, virtual]

An implementation of a modified version of the Shannon entropy function as a wavelet packet cost function. This is described in section 8.3.2 of Ripples in Mathematics by Jensen and la Cour-Harbo. The log function here is the natural log (sometimes denoted as ln()). Note that the result of the entropy function is always negative. Reimplemented from costbase. Definition at line 21 of file costshannon.cpp. { assert( node != 0 ); size_t len = node->length(); const double *a = node->getData(); double sum = 0.0; for (int i = 0; i < len; i++) { double val = 0.0; if (a[i] != 0.0) { double square = a[i] * a[i]; val = square * log( square ); } sum = sum + val; } return -sum; } // costshannon

---

The documentation for this class was generated from the following files:

• costshannon.h
• costshannon.cpp

---