2.11.9 dfilter(Pro)

1 Menu Information
2 Brief Information
3 Additional Information
4 Command Line Usage
5 X-Function Execution Options
6 Variables
7 Examples
8 More Information
9 Related X-Functions

Menu Information

Analysis : Signal Processing : IIR Filter

Brief Information

Create and apply an IIR filter

Additional Information

Minimum Origin Version Required: Origin 9.0 SR0

This feature is for OriginPro only.

Command Line Usage

dfilter method:=cheby1 order:=5 sample:=1000 wn:=50 filtfilt:=1 coef:=[<input>]<new>;

X-Function Execution Options

Please refer to the page for additional option switches when accessing the x-function from script

Variables

Display Name	Variable Name	I/O and Type	Default Value	Description
Input Signal	iy	Input XYRange	<active>	Specify the input signal.
Response Type	type	Input int	0	Specify the response type of filter. Option list: low:Low Pass Allow low frequency components to pass. high:High Pass Allow high frequency components to pass. bandpass:Band Pass Allow frequency components within a specified range to pass. bandstop:Band Stop Allow frequency components outside a specified range to pass.
Method	method	Input int	0	Specify the filter design method. Option list: butter:Butterworth Butterworth filter design. cheby1:Chebyshev Type I Chebyshev Type I filter design. cheby2:Chebyshev Type II Chebyshev Type II filter design. elliptic:Elliptic Elliptic filter design.
Filter Order	order	Input double	10	Specify the filter order.
Unit	unit	Input int	0	Specify the unit for the frequency settings. Option list: hz:Hz Use Hz as the unit when specifying the frequency specification. normalize:Normalize to (0,1) The specified frequency is normalized to the region from 0 to 1. It is calculated by Frequency(Hz)/(SampleFrequency(Hz)/2), where SampleFrequency(Hz)/2 is the Nyquist frequency.
Sample Frequency (Fs)	sample	Input double	<auto>	Specify the sampling frequency, available when the Unit is Hz.
Cutoff Frequency (Fc)	wn	Input double	<auto>	When Filter Order is specified (not minimum), this variable is used to specify the cutoff frequency for the low pass and high pass.
Cutoff Frequency 1 (Fc1)	wn1	Input double	<auto>	When Filter Order is specified (not minimum), this variable is used to specify the first cutoff frequency for the band pass and band stop.
Cutoff Frequency 2 (Fc2)	wn2	Input double	<auto>	When Filter Order is specified (not minimum), this variable is used to specify the second cutoff frequency for the band pass and band stop.
Pass Frequency	wp	Input double	<auto>	When Filter Order is minimum, this variable is used to specify the pass frequency for the low pass and high pass.
Stop Frequency	ws	Input double	<auto>	When Filter Order is minimum, this variable is used to specify the stop frequency for the low pass and high pass.
Pass Frequency 1	wp1	Input double	<auto>	When Filter Order is minimum, this variable is used to specify the first pass frequency for the band pass and band stop.
Stop Frequency 1	ws1	Input double	<auto>	When Filter Order is minimum, this variable is used to specify the first stop frequency for the band pass and band stop.
Pass Frequency 2	wp2	Input double	<auto>	When Filter Order is minimum, this variable is used to specify the second pass frequency for the band pass and band stop.
Stop Frequency 2	ws2	Input double	<auto>	When Filter Order is minimum, this variable is used to specify the second stop frequency for the band pass and band stop.
Passband Ripple	rp	Input double	1	Specify the pass band ripples in dB.
Stopband Attenuation	rs	Input double	80	Specify the stop band attenuation in dB.
Forward-Backward Filtering	filtfilt	Input int	0	Specify whether to perform both forward and backward filtering on the input signal.
SOS Matrix	sos	Output ReportData	[<input>]<new>	Output the designed IIR filter as the second order section (SOS) parameters form.
Zeros Poles and Gain	zpk	Output ReportData	[<input>]<new>	Output the designed IIR filter as the zero-pole-gain form.
State-Space Form	abcd	Output ReportData	[<input>]<new>	Output the designed IIR filter as the state-space form.
Coefficients	coef	Output ReportData	[<input>]<new>	Output the designed IIR filter as the numerator coefficients and the denominator coefficients.
Output Signal	oy	Output XYRange	(<input>,<new>)	The output signal after filtering by the designed IIR filter.

Examples

This example will show how to perform high pass with Butterworth method.

Create a new project and import the data file <Origin Installation Directory>\Samples\Signal Processing\EMG Recording.dat.
Highlight column B, and make a line plot by menu Plot: Line: Line.
Activate the graph, select menu Analysis: Signal Processing: IIR Filter to open the dialog, and then set the parameters as the following image shows.
Response Type: High Pass

Filter Order: 6

Cutoff Frequency (Fc): 20

Forward-Backwrad Filtering: checked
Click the OK button, the result will plot together with the original signal. Zoom in the graph between about from 12.1 to 13.5. The result is shown in the following image.