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Measures of Spread (Standard Deviation and Variance) (G Dataflow)

Version:
    Last Modified: March 15, 2017

    Computes the mean, standard deviation, and variance of the values in a sequence.

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    reset

    A Boolean that specifies whether to reset the internal state of the node.

    True Resets the internal state of the node.
    False Does not reset the internal state of the node.

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

    Default: False

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    x

    The input sequence.

    This input accepts a double-precision, floating-point number or a 1D array of double-precision, floating-point numbers.

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    weighting

    Weighting mode that this node uses to compute the input sequence.

    Name Description
    Sample

    Calculates the sample standard deviation and variance.

    Population

    Calculates the population standard deviation and variance.

    Default: Sample

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    sample length

    Length of each set of data.

    The node performs computation for each set of data. sample length must be greater than zero.

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

    Default: 100

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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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    mean

    Mean, or average, of the values in the input sequence.

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    standard deviation

    Standard deviation calculated from the values in the input sequence.

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    variance

    Calculated variance of the values in the input sequence.

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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 Computing the Mean, Deviation, and Variance

    The node calculates the output values using the following equations.

    μ = 1 n i = 0 n 1 x i

    where μ is mean and n is the number of elements in x.

    σ 2 = 1 n i = 0 n 1 ( x i μ ) 2

    where

    • σ is standard deviation
    • σ 2 is variance
    • μ is mean
    • w is n when weighting is Population and (n - 1) when weighting is Sample

    Where This Node Can Run:

    Desktop OS: Windows

    FPGA: This product does not support FPGA devices


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