| 1 | /*************************************************************************** |
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| 2 | * blitz/array/convolve.cc One-dimensional convolution |
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| 3 | * |
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| 4 | * $Id$ |
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| 5 | * |
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| 6 | * Copyright (C) 1997-2011 Todd Veldhuizen <tveldhui@acm.org> |
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| 7 | * |
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| 8 | * This file is a part of Blitz. |
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| 9 | * |
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| 10 | * Blitz is free software: you can redistribute it and/or modify |
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| 11 | * it under the terms of the GNU Lesser General Public License |
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| 12 | * as published by the Free Software Foundation, either version 3 |
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| 13 | * of the License, or (at your option) any later version. |
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| 14 | * |
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| 15 | * Blitz is distributed in the hope that it will be useful, |
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| 16 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 17 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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| 18 | * GNU Lesser General Public License for more details. |
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| 19 | * |
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| 20 | * You should have received a copy of the GNU Lesser General Public |
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| 21 | * License along with Blitz. If not, see <http://www.gnu.org/licenses/>. |
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| 22 | * |
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| 23 | * Suggestions: blitz-devel@lists.sourceforge.net |
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| 24 | * Bugs: blitz-support@lists.sourceforge.net |
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| 25 | * |
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| 26 | * For more information, please see the Blitz++ Home Page: |
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| 27 | * https://sourceforge.net/projects/blitz/ |
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| 28 | * |
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| 29 | ****************************************************************************/ |
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| 30 | |
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| 31 | #ifndef BZ_ARRAY_CONVOLVE_CC |
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| 32 | #define BZ_ARRAY_CONVOLVE_CC |
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| 33 | |
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| 34 | BZ_NAMESPACE(blitz) |
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| 35 | |
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| 36 | template<typename T> |
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| 37 | Array<T,1> convolve(const Array<T,1>& B, const Array<T,1>& C) |
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| 38 | { |
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| 39 | int Bl = B.lbound(0), Bh = B.ubound(0); |
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| 40 | int Cl = C.lbound(0), Ch = C.ubound(0); |
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| 41 | |
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| 42 | int lbound = Bl + Cl; |
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| 43 | int ubound = Bh + Ch; |
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| 44 | |
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| 45 | Array<T,1> A(Range(lbound,ubound)); |
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| 46 | |
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| 47 | T result; |
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| 48 | for (int i=lbound; i <= ubound; ++i) |
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| 49 | { |
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| 50 | int jl = i - Ch; |
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| 51 | if (jl < Bl) |
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| 52 | jl = Bl; |
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| 53 | |
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| 54 | int jh = i - Cl; |
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| 55 | if (jh > Bh) |
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| 56 | jh = Bh; |
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| 57 | |
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| 58 | result = 0; |
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| 59 | for (int j=jl; j <= jh; ++j) |
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| 60 | result += B(j) * C(i-j); |
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| 61 | |
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| 62 | A(i) = result; |
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| 63 | } |
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| 64 | |
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| 65 | return A; |
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| 66 | } |
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| 67 | |
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| 68 | BZ_NAMESPACE_END |
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| 69 | |
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| 70 | #endif // BZ_ARRAY_CONVOLVE_CC |
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| 71 | |
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