kopia lustrzana https://github.com/mobilinkd/tnc3-firmware
53 wiersze
956 B
C++
53 wiersze
956 B
C++
// Copyright 2015-2020 Rob Riggs <rob@mobilinkd.com>
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// All rights reserved.
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#pragma once
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#include <array>
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#include <cstring>
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#include <cstddef>
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namespace mobilinkd { namespace tnc {
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template <size_t N>
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struct IirFilter {
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const std::array<float, N>& numerator_;
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const std::array<float, N>& denominator_;
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std::array<float, N> history_;
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size_t size_;
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IirFilter(const std::array<float, N>& b,
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const std::array<float, N>& a)
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: numerator_(b), denominator_(a)
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, history_(), size_(N)
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{
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history_.fill(0.0f);
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}
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~IirFilter() {}
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float operator()(float input)
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{
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for(size_t i = size_ - 1; i != 0; i--) history_[i] = history_[i - 1];
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history_[0] = input;
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for (size_t i = 1; i != size_; i++) {
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history_[0] -= denominator_[i] * history_[i];
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}
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float result = 0;
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for (size_t i = 0; i != size_; i++) {
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result += numerator_[i] * history_[i];
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}
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return result;
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}
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};
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}} // mobilinkd::tnc
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