IntervalOptions Struct Reference

An instance of this class, taken by GetIntervals() and PolynomialFilterInterface::setFilter(), is a collection of options to determine the intervals which decides the base filter. More...

#include <polyfilt.h>

Public Member Functions
	IntervalOptions ()
	A default constructor to set default parameters.

Public Attributes
Vector	intervalWeights
	Interval weights (default 100,1,1,1,100). More...
Real	transitionIntervalRatio
	The (relative) length of transition interval (default 0.6), effective only for high-pass filters, and low-pass filters with conversion.
bool	reverseInterval
	This parameter tells whether to reverse the interval or not. It is effective only for mid-pass filters (default false).
Real	initialPlateau
	Initial length of ‘plateau’, relative to the length of the interval of desired eigenvalues (default 0.1), effective only for mid-pass filters.
Real	plateauShrinkRate
	The rate at which the plateau shrinks at each iteration (default 1.5), effective only for mid-pass filters.
Real	initialShiftStep
	Initial shift step, relative to the length of the interval of desired eigenvalues (default 0.01), effective only for mid-pass filters.
Real	shiftStepExpansionRate
	The rate at which the shift step expands (default 1.5), effective only for mid-pass filters.
mkIndex	maxInnerIter
	Maximum number of inner iterations (default 30), effective only for mid-pass filters.
Real	yLimitTol
	A mid-pass filter P(x) should have P(a1)=P(b1), where [a1,b1] is the interval of desired eigenvalues; yLimitTol (default 0.0001) is the tolerance allowed for |P(a1)-P(b1)|.
mkIndex	maxOuterIter
	Maximum number of outer iterations (default 50).
mkIndex	numGridPoints
	Number of grid points, used to measure the maximum function value of the polynomial P(z) for z not in the interval in which the eigenvalues are sought (default 200). More...
Real	yBottomLine
	This is the bottom line (default 0.001) which the function value of the polynomial must be greater than for z is in the interval of desired eigenvalues.
Real	yRippleLimit
	The limit of height of ripples (not in the interval of desired eigenvalues) relative to the bottom of polynomial values for z in the interval of desired eigenvalues (default 0.8).

Detailed Description

An instance of this class, taken by GetIntervals() and PolynomialFilterInterface::setFilter(), is a collection of options to determine the intervals which decides the base filter.

Member Data Documentation

intervalWeights

Vector IntervalOptions::intervalWeights

Interval weights (default 100,1,1,1,100).

Remarks

For mid-pass filters, there are 5 intervals, including 2 transition intervals. So all the 5 weights intervalWeights(1),...,intervalWeights(5) are used.

For high-pass filters (and low-pass filters with conversion), there are 3 intervals, including 1 transition interval. So only the first 3 weights intervalWeights(1),intervalWeights(2),intervalWeights(3) are used.

numGridPoints

mkIndex IntervalOptions::numGridPoints

Number of grid points, used to measure the maximum function value of the polynomial P(z) for z not in the interval in which the eigenvalues are sought (default 200).

Remarks

The value of numGridPoints will automatically be increased if it is too small.

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The documentation for this struct was generated from the following file:

• polyfilt.h