mirror of
https://gitee.com/mirrors_PX4/PX4-Autopilot.git
synced 2026-07-19 03:30:35 +08:00
Daniel Agar
76 lines
2.5 KiB
C++
76 lines
2.5 KiB
C++
/****************************************************************************
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*
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* Copyright (c) 2020-2022 PX4 Development Team. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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* 3. Neither the name PX4 nor the names of its contributors may be
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* used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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****************************************************************************/
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#include <matrix/math.hpp>
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#ifndef EKF_UTILS_HPP
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#define EKF_UTILS_HPP
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// Use Kahan summation algorithm to get the sum of "sum_previous" and "input".
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// This function relies on the caller to be responsible for keeping a copy of
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// "accumulator" and passing this value at the next iteration.
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// Ref: https://en.wikipedia.org/wiki/Kahan_summation_algorithm
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inline float kahanSummation(float sum_previous, float input, float &accumulator)
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{
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const float y = input - accumulator;
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const float t = sum_previous + y;
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accumulator = (t - sum_previous) - y;
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return t;
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}
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namespace ecl
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{
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inline float powf(float x, int exp)
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{
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float ret;
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if (exp > 0) {
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ret = x;
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for (int count = 1; count < exp; count++) {
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ret *= x;
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}
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return ret;
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} else if (exp < 0) {
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return 1.0f / ecl::powf(x, -exp);
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}
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return 1.0f;
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}
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} // namespace ecl
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#endif // EKF_UTILS_HPP
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