Filters a set of data with a digital Elliptic filter.

Syntax

OutSignal = EllipFilter(Order,Fc,PassMag,StopMag,InSignal)

OutSignal = EllipFilter(Order,Fc,PassMag,StopMag,Band,InSignal)

OutSignal = EllipFilter(Order,Fc1,Fc2,PassMag,StopMag,InSignal)

Arguments

Name

Description

Order

A positive integer specifying the order of the filter. For band pass and band stop filter, the order is twice this value.

Fc

The corner frequency in Hz of a low pass or high pass filter, or a vector of two corner frequencies for a band pass or band stop filter. For a digital filter, Fc is normalized by the Nyquist frequency and has values in the interval (0,1). For an analog filter, Fc has positive value(s).

Band

(optional)

The filter band specifier. When Fc is a value, Band can be either ‘low’ (default) or ‘high.’ When Fc is a vector, Band is omitted for a band pass filter and ‘stop’ for a band stop filter.

Fc1, Fc2

For the Templex™ style convention, Fc1 and Fc2 are the normalized corner frequencies in Hz of a digital filter. For a low pass filter, Fc1 = 0. For a high pass filter, Fc2 = 0 or 1. For a band pass filter, Fc1 < Fc2. For a band stop filter, Fc1 > Fc2.

PassMag

Magnitude attenuation in decibels (dB) at the nonzero corner frequencies specified by Fc. This is also called the pass band ripple. Must be negative.

StopMag

Magnitude attenuation in decibels (dB) in the stop band. This is also called the stop band ripple. Must be negative.

InSignal

A vector of real data to be filtered.

Output

Name

Description

Outsignal

A vector of filtered data. Same size as the input data.

Example

Filter a vector of data with a low-pass second order Elliptic filter, with a corner frequency at 250 Hz, and a corresponding pass band and stop band responses of -3dB and -20dB, where the data sampling frequency is 1000 Hz.

Syntax

OutData = EllipFilter(2,0,250/500,-3,-20,InData)

Result

OutData is a vector of filtered data.

See Also:

ButterFilter

Cheby1Filter

Cheby2Filter