FIdConvol
Routine
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void FIdConvol (const double x[], double y[], int Nout, const double h[],
int Ncof)
Purpose
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Filter a signal with an FIR filter
Description
The procedure convolves a set of filter coefficients with an array of data.
The input array is x[.]. The first lmem = Ncof-1 samples of x[.] are past
inputs. The first output point is calculated with filter coefficient h[0]
aligned with x[lmem]. The last output point is calculated with h[0] aligned
with x[lmem+(Nout-1)].
The output array can share storage with the input array, with the output data
overlaying the input data. Consider an array x[] with lmem+Nout elements.
The first lmem elements are past input samples; the next Nout values are new
input samples. To share input/output storage, invoke this routine as
FIconvol (x, x, Nout, h, Ncof)
On return, the first Nout elements of x[] are the output values. The last
lmem elements are the past input values needed for the next invocation of
FIconvol.
Parameters
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-> const double x[]
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Input array of data. Let lmem=Ncof-1. The first output point point is
calculated as follows
y[0] = h[0]*x[lmem] + h[1]*x[lmem-1] + h[2]*x[lmem-2] + ...
The array x must have lmem+((Nout-1))+1 elements.
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<- double y[]
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Output array of samples. The order of operations is such that this array
can share storage with the array x.
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-> int Nout
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Number of output samples to be calculated
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-> const double h[]
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Array of Ncof filter coefficients
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-> int Ncof
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Number of filter coefficients
Author / revision
P. Kabal
/ Revision 1.1 2005/02/01
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