FILTER
Returns a 1xN array of filtered input values, where N is the number of input values. The coefficients of the transfer function define the filter.
Format
FILTER (Independent Variable, Dependent Variable, Numerator Coefficients, Denominator Coefficients, Filtering Method)
Arguments
Independent Variable | A 1xN array of independent values. |
Dependent Variable | A 1xN array of dependent values as a function of the independent values. |
Numerator Coefficients | A set of numerator coefficients in the transfer function. |
Denominator Coefficients | A set of denominator coefficients in the transfer function. The number of denominator coefficients can't be lower than the number of numerator coefficients. |
Filtering Method | There are two filtering methods: continuous and discrete. ■Continuous - The continuous (or analog) filter, transforms the input data into frequency space, passes it through the transfer function, and returns it to physical space. A nonzero value indicates the use of the continuous filter. In the following equations, the notation is defined as follows: ■a = user-supplied numerator coefficient ■b = user-supplied denominator coefficient ■z = dependent value ■n = number of numerator coefficients ■m = number of denominator coefficients The numerator coefficients for a continuous filter are used as follows:  The denominator coefficients for a continuous filter are used as follows:  ■Discrete - The discrete (or digital) filter applies the transfer function directly to the input data stream in physical space. A 0 indicates the use of the discrete filter. The numerator coefficients for a discrete filter are used as follows:  The denominator coefficients for a continuous filter are used as follows:  |
Example
The following function returns a 1xN array of numbers that represent the filtered data:
FILTER(.mod1.FUNC_MEA_1.TIME, .mod1.FUNC_MEA_1.Q, {1.0,0,0}, {1.0,12.7,81.0}, 1)