[2733] | 1 | // |
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| 2 | // C++ Implementation: BufferedLinearInterpolator1D |
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| 3 | // |
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| 4 | // Description: |
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| 5 | // |
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| 6 | // |
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| 7 | // Author: Takeshi Nakazato <takeshi.nakazato@nao.ac.jp>, (C) 2012 |
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| 8 | // |
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| 9 | // Copyright: See COPYING file that comes with this distribution |
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| 10 | // |
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| 11 | // |
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| 12 | #include <assert.h> |
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| 13 | |
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| 14 | #include "BufferedLinearInterpolator1D.h" |
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| 15 | |
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| 16 | namespace asap { |
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| 17 | |
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| 18 | template <class T, class U> |
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| 19 | BufferedLinearInterpolator1D<T, U>::BufferedLinearInterpolator1D() |
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| 20 | : Interpolator1D<T, U>(), |
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| 21 | reusable_(false) |
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| 22 | {} |
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| 23 | |
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| 24 | template <class T, class U> |
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| 25 | BufferedLinearInterpolator1D<T, U>::~BufferedLinearInterpolator1D() |
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| 26 | {} |
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| 27 | |
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| 28 | template <class T, class U> |
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| 29 | void BufferedLinearInterpolator1D<T, U>::setData(T *x, U *y, unsigned int n) |
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| 30 | { |
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| 31 | Interpolator1D<T, U>::setData(x, y, n); |
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| 32 | reusable_ = false; |
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| 33 | } |
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| 34 | |
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| 35 | template <class T, class U> |
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| 36 | void BufferedLinearInterpolator1D<T, U>::setX(T *x, unsigned int n) |
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| 37 | { |
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| 38 | Interpolator1D<T, U>::setX(x, n); |
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| 39 | reusable_ = false; |
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| 40 | } |
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| 41 | |
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| 42 | template <class T, class U> |
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| 43 | U BufferedLinearInterpolator1D<T, U>::interpolate(T x) |
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| 44 | { |
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| 45 | assert(this->isready()); |
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| 46 | if (this->n_ == 1) |
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| 47 | return this->y_[0]; |
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| 48 | |
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| 49 | unsigned int i; |
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| 50 | bool b = (reusable_ && x == xold_); |
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| 51 | if (b) { |
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| 52 | i = prev_; |
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| 53 | } |
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| 54 | else { |
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| 55 | i = this->locator_->locate(x); |
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| 56 | prev_ = i; |
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| 57 | xold_ = x; |
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| 58 | } |
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| 59 | |
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| 60 | // do not perform extrapolation |
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| 61 | if (i == 0) { |
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| 62 | return this->y_[i]; |
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| 63 | } |
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| 64 | else if (i == this->n_) { |
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| 65 | return this->y_[i-1]; |
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| 66 | } |
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| 67 | |
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| 68 | // linear interpolation |
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| 69 | if (!b) |
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| 70 | factor_ = (x - this->x_[i-1]) / (this->x_[i] - this->x_[i-1]); |
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| 71 | U y = this->y_[i-1] + (this->y_[i] - this->y_[i-1]) * factor_; |
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| 72 | reusable_ = true; |
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| 73 | return y; |
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| 74 | } |
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| 75 | |
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| 76 | } |
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