Chebyshev Type II

Performs the n-th order Chebyshev Type II filter on the signal S and can be used to remove high frequency noise. A detailed description of the expected arguments is:

S, the data which shall be filtered,
w, the desired cutoff frequency (if the filter type ft is LOWPASS or HIGHPASS w must be a scalar between 0 and 0.5/T and if the filter type is BANDPASS or BANDSTOP the filter expects a 2-dimensional vector with lower cutoff FL and upper cutoff FU with 0 < FL < FU < 0.5/T), where T is the smallest time between two samples of S,
e > 0, the passband ripple according e in figure Filter Comparison,
n, the order of the filter,
ft, the filter type,
it, the interpolation type (used if S is not equally spaced),
d_start and d_end, the start and end slope for the interpolation (see function interpolate() for more information)
c₀ and c_E, the specified pre-charging method (ZERO means a pre-charging with zeros and CONSTANT a pre-charging with the first data point)
b, a boolean value which specifies how the filter shall be performed (if b is set to TRUE, S will be filtered first forward and afterwards backward, else it will only be filtered forward).

Syntax

chebyTwoFilter(S, w, e, n, ft, it, d_start, d_end, c₀, c_E, b)

Types

	Variable Name	Value Type	Variable Type
Arguments:	S	real	signal, xy-data
	w	real	scalar, vector
	e	real	scalar
	n	real	scalar
	ft	FilterType	LOWPASS, HIGHPASS, BANDPASS, BANDSTOP
	it	InterpolationType	LINEAR, QUAD, SPLINE
	d_start	real	scalar
	d_end	real	scalar
	c₀	ConditionType	ZERO, CONSTANT
	c_E	ConditionType	ZERO, CONSTANT
	b	bool	boolean
Result:		real	signal, xydata

Calculator Input

Use the chebyTwoFilter button to complete the operation.