2010-11-08 15:18:07 +00:00
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/* libiir/src/docs/MainPage.dox
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*
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* Copyright: ©2010, Laurence Withers.
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* Author: Laurence Withers <l@lwithers.me.uk>
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* License: GPLv3
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*/
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/*! \mainpage
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This library allows the implementation of arbitrary IIR filters in C. It has
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functions for generating and manipulating filters in terms of coefficients, for
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chaining arbitrary filters together, and for generating coefficients for some
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common types of filter. See \ref iir_structure for a definition of the IIR
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filter equation.
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\section creation Filter creation
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At a high level, filters may be specified as strings. See \ref string_desc for
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the required format and \ref iir_parse() for a C function returning a filter
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instance from such a string.
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Otherwise, the library user must first create a set of coefficients using
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\ref iir_coeff_new(). Any number of filters can then be instantiated using that
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set of coefficients with \ref iir_filter_new(), or the coefficients can be
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chained on to the end of an existing filter instance with
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\ref iir_filter_chain(). See \ref libiir_common_filters for functions to generate
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2010-11-08 15:18:07 +00:00
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coefficients.
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\section operation Filter operation
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The function \ref iir_filter() will actually process an input sample through the
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coefficient chain and produce the output sample. Effectively it produces
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<code>y(t)</code> given <code>x(t)</code>.
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A filter may be copied, possibly including its state (for initial conditions),
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using the function \ref iir_filter_copy().
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\section tools Tools
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In the <code>tests</code> directory are some simple tools for examining and
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experimenting with filters. <code>run_filter</code> takes a stream of input
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samples <code>x(t)</code> and produces the filtered output samples
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<code>y(t)</code>.
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Perhaps more interesting is <code>plot_filter</code> (requires GNUplot to be
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installed) which will generate a Bode plot for a given filter chain. Note the
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phase response can be a little rough due to the simplistic time-domain analysis
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of the output signal's phase.
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*/
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/* options for text editors
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kate: replace-trailing-space-save true; space-indent true; tab-width 4;
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vim: expandtab:ts=4:sw=4:syntax=doxygen
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*/
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