Table Of Contents
Filter Design (Smoothing) (G Dataflow)
Designs filter coefficients for a smoothing filter. You can use this node to design a moving-average FIR filter or an exponentially-averaging IIR filter.
Programming Patterns
To filter a sequence of data, wire the filter output to the Filtering node.
type
The type of smoothing filter to design.
| Name | Description |
|---|---|
| moving average | Yields forward-only (FIR) coefficients. |
| exponential | Yields first-order IIR coefficients. |
Default: moving average
half-width
Half-width of the moving-average filter in samples. For a half-width of M, the full width of the moving-average filter is N = 1 + 2*M samples. Therefore, the full width N is always an odd number of samples.
Default: 1
shape
The shape of the moving-average filter.
| Name | Description |
|---|---|
| rectangular | Applies a rectangular moving-average filter to the samples. All samples in the moving-average window are weighted equally in computing each smoothed output sample. |
| triangular | Applies a triangular moving-average filter to the samples. The peak is centered in the middle of the moving-average window, ramping down symmetrically on both sides of the center sample. |
Default: rectangular
time constant
Time constant of the exponential-weighting filter in seconds.
Default: 0.1
error in
Error conditions that occur before this node runs.
The node responds to this input according to standard error behavior.
Standard Error Behavior
Many nodes provide an error in input and an error out output so that the node can respond to and communicate errors that occur while code is running. The value of error in specifies whether an error occurred before the node runs. Most nodes respond to values of error in in a standard, predictable way.
Default: No error
sampling frequency
Sampling frequency in samples per second.
Default: 0.01
filter
Output smoothing filter.
filter structure
Structure of the output filter.
forward coefficients
The forward coefficients of an IIR filter.
reverse coefficients
The reverse, or feedback, coefficients of an IIR filter.
sampling frequency
The sampling frequency in Hz.
error out
Error information.
The node produces this output according to standard error behavior.
Standard Error Behavior
Many nodes provide an error in input and an error out output so that the node can respond to and communicate errors that occur while code is running. The value of error in specifies whether an error occurred before the node runs. Most nodes respond to values of error in in a standard, predictable way.
Where This Node Can Run:
Desktop OS: Windows
FPGA: Not supported
Web Server: Not supported in VIs that run in a web application