\"  ffilters.roff from ObjectProDSP 0.2
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.H 1 "Filtering operations"

Nodes `CxFir', `RlFir', `Demod', `Interpolate' and
`Integrate' perform various filtering operations in their input.
They are under `objects' and `dsp processing'. 

`CxFir' and `RlFir' are standard finite impulse response FIR filters
for real and complex data respectively. They both support arbitrary
integer resampling of their input data streams.

`DcTrap' is a simple notch filter at 0 hz.

`Demod' does complex demodulation by an arbitrary frequency,
i. e. it multiplies its input by
\".LINE $e^{-i\omega N}$ where $\omega$ is an angle that
exp(-i W N) where W is an angle that
translates to a demodulation frequency and
N is the sample index.
Demodulation is also a built in option in `CxFir'.

`Interpolate' uses linear interpolation to generate an output
data stream with a different sample rate then its input data stream.

`Integrate' does a sliding window sum of its input to generate its output.
It can produce output at any integral divisor of its input. 


