source: Sophya/trunk/Poubelle/DPC:FitsIOServer/Blitz/blitz/array/reduce.h@ 2747

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1/***************************************************************************
2 * blitz/array/reduce.h Reductions of an array (or array expression) in a
3 * single rank: sum, mean, min, minIndex, max, maxIndex,
4 * product, count, any, all
5 *
6 * $Id: reduce.h,v 1.1.1.1 1999-11-26 16:37:07 ansari Exp $
7 *
8 * Copyright (C) 1997,1998 Todd Veldhuizen <tveldhui@seurat.uwaterloo.ca>
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License
12 * as published by the Free Software Foundation; either version 2
13 * of the License, or (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 *
20 * Suggestions: blitz-suggest@cybervision.com
21 * Bugs: blitz-bugs@cybervision.com
22 *
23 * For more information, please see the Blitz++ Home Page:
24 * http://seurat.uwaterloo.ca/blitz/
25 *
26 ***************************************************************************
27 * $Log: not supported by cvs2svn $
28 * Revision 1.1.1.1 1999/04/09 17:59:04 ansari
29 * Creation module DPC/Blitz (blitz 0.4) Reza 09/04/99
30 *
31 * Revision 1.2 1998/03/14 00:04:47 tveldhui
32 * 0.2-alpha-05
33 *
34 * Revision 1.1 1997/07/16 14:51:20 tveldhui
35 * Update: Alpha release 0.2 (Arrays)
36 *
37 */
38
39#ifndef BZ_ARRAYREDUCE_H
40#define BZ_ARRAYREDUCE_H
41
42#ifndef BZ_ARRAYEXPR_H
43 #error <blitz/array/reduce.h> must be included after <blitz/array/expr.h>
44#endif
45
46#ifndef BZ_REDUCE_H
47 #include <blitz/reduce.h>
48#endif
49
50BZ_NAMESPACE(blitz)
51
52template<class T_expr, int N_index, class T_reduction>
53class _bz_ArrayExprReduce {
54
55public:
56 typedef _bz_typename T_reduction::T_numtype T_numtype;
57 typedef T_expr T_ctorArg1;
58 typedef T_reduction T_ctorArg2;
59
60 enum { numArrayOperands = BZ_ENUM_CAST(T_expr::numArrayOperands),
61 numIndexPlaceholders = BZ_ENUM_CAST(T_expr::numIndexPlaceholders) + 1,
62 rank = BZ_ENUM_CAST(T_expr::rank) - 1 };
63
64 _bz_ArrayExprReduce(const _bz_ArrayExprReduce<T_expr,N_index,T_reduction>&
65 reduce)
66 : reduce_(reduce.reduce_), iter_(reduce.iter_)
67 {
68 }
69
70 _bz_ArrayExprReduce(T_expr expr)
71 : iter_(expr)
72 { }
73
74 _bz_ArrayExprReduce(T_expr expr, T_reduction reduce)
75 : iter_(expr), reduce_(reduce)
76 { }
77
78 int lbound(int rank)
79 { return iter_.lbound(rank); }
80
81 int ubound(int rank)
82 { return iter_.ubound(rank); }
83
84 template<int N_destRank>
85 T_numtype operator()(const TinyVector<int, N_destRank>& destIndex)
86 {
87 BZPRECHECK(N_destRank == N_index,
88 "Array reduction performed over rank " << N_index
89 << " to produce a rank " << N_destRank << " expression." << endl
90 << "You must reduce over rank " << N_destRank << " instead.");
91
92 TinyVector<int, N_destRank + 1> index;
93
94 // This metaprogram copies elements 0..N-1 of destIndex into index
95 _bz_meta_vecAssign<N_index, 0>::assign(index, destIndex,
96 _bz_update<int,int>());
97
98 int lbound = iter_.lbound(N_index);
99 int ubound = iter_.ubound(N_index);
100
101 // NEEDS_WORK: replace with tiny(int()) and huge(int()) once
102 // <limits> widely available
103 BZPRECHECK((lbound != INT_MIN) && (ubound != INT_MAX),
104 "Array reduction performed over rank " << N_index
105 << " is unbounded." << endl
106 << "There must be an array object in the expression being reduced"
107 << endl << "which provides a bound in rank " << N_index << ".");
108
109 reduce_.reset();
110
111 for (index[N_index] = iter_.lbound(N_index);
112 index[N_index] <= ubound; ++index[N_index])
113 {
114 if (!reduce_(iter_(index), index[N_index]))
115 break;
116 }
117
118 return reduce_.result(ubound-lbound+1);
119 }
120
121 // If you have a precondition failure on this routine, it means
122 // you are trying to use stack iteration mode on an expression
123 // which contains an index placeholder. You must use index
124 // iteration mode instead.
125 int operator*()
126 {
127 BZPRECONDITION(0);
128 return 0;
129 }
130
131 // See operator*() note
132 void push(int)
133 {
134 BZPRECONDITION(0);
135 }
136
137 // See operator*() note
138 void pop(int)
139 {
140 BZPRECONDITION(0);
141 }
142
143 // See operator*() note
144 void advance()
145 {
146 BZPRECONDITION(0);
147 }
148
149 // See operator*() note
150 void advance(int)
151 {
152 BZPRECONDITION(0);
153 }
154
155 // See operator*() note
156 void loadStride(int)
157 {
158 BZPRECONDITION(0);
159 }
160
161 _bz_bool isUnitStride(int rank) const
162 {
163 BZPRECONDITION(0);
164 return false;
165 }
166
167 void advanceUnitStride()
168 {
169 BZPRECONDITION(0);
170 }
171
172 _bz_bool canCollapse(int,int) const
173 { BZPRECONDITION(0); return _bz_false; }
174
175 T_numtype operator[](int)
176 {
177 BZPRECONDITION(0);
178 return T_numtype();
179 }
180
181 T_numtype fastRead(int)
182 {
183 BZPRECONDITION(0);
184 return T_numtype();
185 }
186
187 int suggestStride(int) const
188 {
189 BZPRECONDITION(0);
190 return 0;
191 }
192
193 _bz_bool isStride(int,int) const
194 {
195 BZPRECONDITION(0);
196 return _bz_true;
197 }
198
199 template<int N_rank>
200 void moveTo(const TinyVector<int,N_rank>& i)
201 {
202 BZPRECONDITION(0);
203 return;
204 }
205
206 void prettyPrint(std::string& str, prettyPrintFormat& format) const
207 {
208 // NEEDS_WORK-- do real formatting for reductions
209 str += "reduce[NEEDS_WORK](";
210 iter_.prettyPrint(str,format);
211 str += ")";
212 }
213
214 template<class T_shape>
215 _bz_bool shapeCheck(const T_shape& shape) const
216 {
217 // NEEDS_WORK-- do a real shape check (tricky)
218 return _bz_true;
219 }
220
221private:
222 _bz_ArrayExprReduce() { }
223
224 T_reduction reduce_;
225 T_expr iter_;
226};
227
228#define BZ_DECL_ARRAY_PARTIAL_REDUCE(fn,reduction) \
229template<class T_expr, int N_index> \
230inline \
231_bz_ArrayExpr<_bz_ArrayExprReduce<_bz_ArrayExpr<T_expr>, N_index, \
232 reduction<_bz_typename T_expr::T_numtype> > > \
233fn(_bz_ArrayExpr<T_expr> expr, const IndexPlaceholder<N_index>&) \
234{ \
235 return _bz_ArrayExprReduce<_bz_ArrayExpr<T_expr>, N_index, \
236 reduction<_bz_typename T_expr::T_numtype> >(expr); \
237} \
238 \
239template<class T_numtype, int N_rank, int N_index> \
240inline \
241_bz_ArrayExpr<_bz_ArrayExprReduce<ArrayIterator<T_numtype,N_rank>, \
242 N_index, reduction<T_numtype> > > \
243fn(const Array<T_numtype, N_rank>& array, \
244 const IndexPlaceholder<N_index>&) \
245{ \
246 return _bz_ArrayExprReduce<ArrayIterator<T_numtype,N_rank>, \
247 N_index, reduction<T_numtype> > (array.begin()); \
248}
249
250BZ_DECL_ARRAY_PARTIAL_REDUCE(sum, ReduceSum)
251BZ_DECL_ARRAY_PARTIAL_REDUCE(mean, ReduceMean)
252BZ_DECL_ARRAY_PARTIAL_REDUCE(min, ReduceMin)
253BZ_DECL_ARRAY_PARTIAL_REDUCE(minIndex, ReduceMinIndex)
254BZ_DECL_ARRAY_PARTIAL_REDUCE(max, ReduceMax)
255BZ_DECL_ARRAY_PARTIAL_REDUCE(maxIndex, ReduceMaxIndex)
256BZ_DECL_ARRAY_PARTIAL_REDUCE(product, ReduceProduct)
257BZ_DECL_ARRAY_PARTIAL_REDUCE(count, ReduceCount)
258BZ_DECL_ARRAY_PARTIAL_REDUCE(any, ReduceAny)
259BZ_DECL_ARRAY_PARTIAL_REDUCE(all, ReduceAll)
260BZ_DECL_ARRAY_PARTIAL_REDUCE(first, ReduceFirst)
261
262/*
263 * Complete reductions
264 */
265
266// Prototype of reduction function
267template<class T_expr, class T_reduction>
268_bz_typename T_reduction::T_resulttype
269_bz_ArrayExprFullReduce(T_expr expr, T_reduction reduction);
270
271#define BZ_DECL_ARRAY_FULL_REDUCE(fn,reduction) \
272template<class T_expr> \
273inline \
274_bz_typename reduction<_bz_typename T_expr::T_numtype>::T_resulttype \
275fn(_bz_ArrayExpr<T_expr> expr) \
276{ \
277 return _bz_ArrayExprFullReduce(expr, \
278 reduction<_bz_typename T_expr::T_numtype>()); \
279} \
280 \
281template<class T_numtype, int N_rank> \
282inline \
283_bz_typename reduction<T_numtype>::T_resulttype \
284fn(const Array<T_numtype, N_rank>& array) \
285{ \
286 return _bz_ArrayExprFullReduce(array.begin(), \
287 reduction<T_numtype>()); \
288}
289
290BZ_DECL_ARRAY_FULL_REDUCE(sum, ReduceSum)
291BZ_DECL_ARRAY_FULL_REDUCE(mean, ReduceMean)
292BZ_DECL_ARRAY_FULL_REDUCE(min, ReduceMin)
293BZ_DECL_ARRAY_FULL_REDUCE(minIndex, ReduceMinIndex)
294BZ_DECL_ARRAY_FULL_REDUCE(max, ReduceMax)
295BZ_DECL_ARRAY_FULL_REDUCE(maxIndex, ReduceMaxIndex)
296BZ_DECL_ARRAY_FULL_REDUCE(product, ReduceProduct)
297BZ_DECL_ARRAY_FULL_REDUCE(count, ReduceCount)
298BZ_DECL_ARRAY_FULL_REDUCE(any, ReduceAny)
299BZ_DECL_ARRAY_FULL_REDUCE(all, ReduceAll)
300BZ_DECL_ARRAY_FULL_REDUCE(first, ReduceFirst)
301
302BZ_NAMESPACE_END
303
304#include <blitz/array/reduce.cc>
305
306#endif // BZ_ARRAYREDUCE_H
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