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Savitzky-Golay Filter (G Dataflow)

Last Modified: March 15, 2017

Filters a signal using a Savitzky-Golay FIR smoothing filter.

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reset

A Boolean that specifies the initialization of the internal state of the node.

True Initializes the internal state to zero.
False Initializes the internal state to the final state from the previous call of this node.

This node automatically initializes the internal state to zero on the first call and runs continuously until this input is True.

This input is available only if you wire a double-precision, floating-point number to signal.

Default: False

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signal

Input signal.

This input accepts the following data types:

  • Double-precision, floating-point number
  • 1D array of double-precision, floating-point numbers
  • 1D array of complex double-precision, floating-point numbers
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side points

The number of data points to each side of the current data point to use for the least-squares minimization.

side points*2 + 1 is the length of the moving window, which must be greater than the polynomial order.

Default: 6

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polynomial order

Order of the polynomial.

Default: 3

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weight

Weighting vector to use in the least squares minimization.

This array must be empty or have a length of side points * 2 + 1.

This input is available only if you wire one of the following data types to signal:

  • 1D array of double-precision, floating-point numbers
  • 1D array of complex double-precision, floating-point numbers
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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.

error in does not contain an error error in contains an error
If no error occurred before the node runs, the node begins execution normally.

If no error occurs while the node runs, it returns no error. If an error does occur while the node runs, it returns that error information as error out.

If an error occurred before the node runs, the node does not execute. Instead, it returns the error in value as error out.

Default: No error

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filtered signal

Filtered signal.

This output can return the following data types:

  • Double-precision, floating-point number
  • 1D array of double-precision, floating-point numbers
  • 1D array of complex double-precision, floating-point numbers
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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.

error in does not contain an error error in contains an error
If no error occurred before the node runs, the node begins execution normally.

If no error occurs while the node runs, it returns no error. If an error does occur while the node runs, it returns that error information as error out.

If an error occurred before the node runs, the node does not execute. Instead, it returns the error in value as error out.

Algorithm for Applying a Savitzky-Golay Filter

The Savitzky-Golay filter smoothes a noisy signal by the piece-by-piece fitting of a polynomial function to the signal. The node performs the fitting by least squares minimization.

Where This Node Can Run:

Desktop OS: Windows

FPGA: This product does not support FPGA devices


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