Image Component Library (ICL)
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The StochasticOptimizer is a tiny frame-work for simple stochastic optimization processes. More...
#include <StochasticOptimizer.h>
Public Types | |
typedef StochasticOptimizerResult< T > | Result |
Result structure. | |
Public Member Functions | |
StochasticOptimizer (int dataDim) | |
create a stochastic optimizer with given data dimension | |
Result | optimize (int maxTimeSteps) |
start optimization process with given step count | |
Result | optimize (T minError, int maxSteps) |
start optimization process with given step count and minimal error stop-criterion | |
Protected Member Functions | |
virtual T * | getData ()=0 |
must return the current data vector | |
virtual T | getError (const T *data)=0 |
must return current error value (>=0) | |
virtual const T * | getNoise (int currentTime, int endTime)=0 |
returns a noise vector (of size dataDim, which was passed to the constructor) | |
virtual void | reinitialize ()=0 |
this function is called before the optimization is started | |
virtual void | notifyProgress (int t, int numSteps, int startError, int currBestError, int currError, const T *data, int dataDim) |
a pure utility function, which can be implemented in derived classes to notify optization progress (somehow) | |
Private Attributes | |
int | m_dataDim |
internal data-dimension variable |
The StochasticOptimizer is a tiny frame-work for simple stochastic optimization processes.
Stochastic optimization is minimization of an error function, which depends on a set of latent variables (here: called data). The naive approach origins from starting configuration, which must be created by the pure virtual reinitialize function. Now in each optimization step, the current data vector is changed slightly using an additive noise vector which must be provided by the also pure virtual getNoise-function. If the error arising from the changed data is less then the current minimal error, then the change data vector use hold, otherwise the last change of data is reverted. This procedure is iterated until either a maximum number of iterations is reached or until a given minimal error is reached.
NEW** now this class is a template (defined for float and double)
typedef StochasticOptimizerResult<T> icl::math::StochasticOptimizer< T >::Result |
Result structure.
icl::math::StochasticOptimizer< T >::StochasticOptimizer | ( | int | dataDim | ) |
create a stochastic optimizer with given data dimension
virtual T* icl::math::StochasticOptimizer< T >::getData | ( | ) | [protected, pure virtual] |
must return the current data vector
data is un-const, as it is changed in each step if the reached error is less then the current best error. Returned pointer must have at least the length of dataDim passed to the constructor
virtual T icl::math::StochasticOptimizer< T >::getError | ( | const T * | data | ) | [protected, pure virtual] |
must return current error value (>=0)
returns the error measurement dependent on given data vector
virtual const T* icl::math::StochasticOptimizer< T >::getNoise | ( | int | currentTime, |
int | endTime | ||
) | [protected, pure virtual] |
returns a noise vector (of size dataDim, which was passed to the constructor)
optionally, the noise-strength might depend on the current time-progress. Therefore, currentTime and endTime is also passed to this functions
virtual void icl::math::StochasticOptimizer< T >::notifyProgress | ( | int | t, |
int | numSteps, | ||
int | startError, | ||
int | currBestError, | ||
int | currError, | ||
const T * | data, | ||
int | dataDim | ||
) | [protected, virtual] |
a pure utility function, which can be implemented in derived classes to notify optization progress (somehow)
Result icl::math::StochasticOptimizer< T >::optimize | ( | int | maxTimeSteps | ) | [inline] |
start optimization process with given step count
Result icl::math::StochasticOptimizer< T >::optimize | ( | T | minError, |
int | maxSteps | ||
) |
start optimization process with given step count and minimal error stop-criterion
virtual void icl::math::StochasticOptimizer< T >::reinitialize | ( | ) | [protected, pure virtual] |
this function is called before the optimization is started
Internally data must be initialized
int icl::math::StochasticOptimizer< T >::m_dataDim [private] |
internal data-dimension variable