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