| 1 | /* |
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| 2 | * $Id: vecdelta.cc,v 1.3 2003/12/11 03:44:22 julianc Exp $ |
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| 3 | * |
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| 4 | * Copyright (C) 1997 Todd Veldhuizen <tveldhui@oonumerics.org> |
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| 5 | * All rights reserved. Please see <blitz/blitz.h> for terms and |
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| 6 | * conditions of use. |
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| 7 | * |
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| 8 | */ |
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| 9 | |
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| 10 | #ifndef BZ_VECDELTA_CC |
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| 11 | #define BZ_VECDELTA_CC |
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| 12 | |
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| 13 | #ifndef BZ_VECGLOBS_H |
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| 14 | #error <blitz/vecdelta.cc> must be included via <blitz/vecglobs.h> |
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| 15 | #endif |
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| 16 | |
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| 17 | BZ_NAMESPACE(blitz) |
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| 18 | |
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| 19 | template<typename P> |
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| 20 | inline |
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| 21 | Vector<BZ_DIFFTYPE(_bz_typename P::T_numtype)> _bz_vec_delta(P expr) |
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| 22 | { |
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| 23 | typedef _bz_typename P::T_numtype T_numtype; |
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| 24 | typedef BZ_DIFFTYPE(T_numtype) T_difftype; |
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| 25 | |
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| 26 | int length = expr._bz_suggestLength(); |
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| 27 | Vector<T_difftype> z(length); |
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| 28 | T_numtype currentElement = 0; |
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| 29 | T_numtype previousElement = 0; |
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| 30 | |
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| 31 | if (expr._bz_hasFastAccess()) |
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| 32 | { |
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| 33 | for (int i=0; i < length; ++i) |
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| 34 | { |
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| 35 | currentElement = expr._bz_fastAccess(i); |
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| 36 | z[i] = currentElement - previousElement; |
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| 37 | previousElement = currentElement; |
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| 38 | } |
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| 39 | } |
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| 40 | else { |
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| 41 | for (int i=1; i < length; ++i) |
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| 42 | { |
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| 43 | currentElement = expr(i); |
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| 44 | z[i] = currentElement - previousElement; |
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| 45 | previousElement = currentElement; |
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| 46 | } |
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| 47 | } |
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| 48 | |
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| 49 | return z; |
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| 50 | } |
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| 51 | |
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| 52 | template<typename P_numtype> |
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| 53 | Vector<BZ_DIFFTYPE(P_numtype)> delta(const Vector<P_numtype>& x) |
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| 54 | { |
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| 55 | return _bz_vec_delta(x); |
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| 56 | } |
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| 57 | |
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| 58 | // delta(expr) |
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| 59 | template<typename P_expr> |
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| 60 | Vector<BZ_DIFFTYPE(_bz_typename P_expr::T_numtype)> delta(_bz_VecExpr<P_expr> x) |
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| 61 | { |
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| 62 | return _bz_vec_delta(x); |
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| 63 | } |
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| 64 | |
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| 65 | // delta(vecpick) |
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| 66 | template<typename P_numtype> |
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| 67 | Vector<BZ_DIFFTYPE(P_numtype)> delta(const VectorPick<P_numtype>& x) |
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| 68 | { |
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| 69 | return _bz_vec_delta(x); |
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| 70 | } |
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| 71 | |
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| 72 | BZ_NAMESPACE_END |
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| 73 | |
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| 74 | #endif // BZ_VECDELTA_CC |
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| 75 | |
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