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Contents of /trunk/escript/src/DataLazy.h

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Revision 1910 - (show annotations)
Thu Oct 23 03:05:28 2008 UTC (11 years, 5 months ago) by jfenwick
Original Path: branches/schroedinger/escript/src/DataLazy.h
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File size: 6929 byte(s)
Branch commit.
Support for ** added.

1
2 /*******************************************************
3 *
4 * Copyright (c) 2003-2008 by University of Queensland
5 * Earth Systems Science Computational Center (ESSCC)
6 * http://www.uq.edu.au/esscc
7 *
8 * Primary Business: Queensland, Australia
9 * Licensed under the Open Software License version 3.0
10 * http://www.opensource.org/licenses/osl-3.0.php
11 *
12 *******************************************************/
13
14
15 #if !defined escript_DataLazy_20081008_H
16 #define escript_DataLazy_20081008_H
17 #include "system_dep.h"
18
19 #include "DataAbstract.h"
20
21 #include <string>
22 #include <functional>
23
24 #include "LocalOps.h" // for tensor_binary_op
25
26 namespace escript {
27
28 enum ES_optype
29 {
30 UNKNOWNOP=0,
31 IDENTITY=1,
32 ADD=2,
33 SUB=3,
34 MUL=4,
35 DIV=5,
36 POW=6,
37 SIN=POW+1,
38 COS=SIN+1,
39 TAN=SIN+2,
40 ASIN=SIN+3,
41 ACOS=SIN+4,
42 ATAN=SIN+5,
43 SINH=SIN+6,
44 COSH=SIN+7,
45 TANH=SIN+8,
46 ERF=SIN+9,
47 ASINH=SIN+10,
48 ACOSH=SIN+11,
49 ATANH=SIN+12,
50 LOG10=ATANH+1,
51 LOG=LOG10+1,
52 SIGN=LOG10+2,
53 ABS=LOG10+3,
54 NEG=LOG10+4,
55 POS=LOG10+5,
56 EXP=LOG10+6,
57 SQRT=LOG10+7,
58 RECIP=LOG10+8,
59 GZ=RECIP+1,
60 LZ=GZ+1,
61 GEZ=GZ+2,
62 LEZ=GZ+3
63 };
64
65 const std::string&
66 opToString(ES_optype op);
67
68 /**
69 \class escript::DataLazy
70 \brief Wraps an expression tree of other DataObjects.
71 The data will be evaluated when required.
72
73
74 NOTE: This class assumes that the Data being pointed at are immutable.
75 */
76
77 class DataLazy;
78
79 typedef POINTER_WRAPPER_CLASS(DataLazy) DataLazy_ptr;
80 typedef POINTER_WRAPPER_CLASS(const DataLazy) const_DataLazy_ptr;
81
82 class DataLazy : public DataAbstract
83 {
84
85 typedef DataAbstract parent;
86 typedef DataTypes::ValueType ValueType;
87 typedef DataTypes::ShapeType ShapeType;
88
89 public:
90 /**
91 \brief Create an IDENTITY DataLazy for the given DataAbstract.
92 \param p DataAbstract to be wrapped.
93 \throws DataException if p is lazy data or it is not constant, tagged or expanded.
94 */
95 ESCRIPT_DLL_API
96 DataLazy(DataAbstract_ptr p);
97
98
99 /**
100 \brief Produce a DataLazy for a unary operation.
101 \param left DataAbstract to be operated on.
102 \param op unary operation to perform.
103 \throws DataException if op is not a unary operation or if p cannot be converted to a DataLazy.
104 Note that IDENTITY is not considered a unary operation.
105 */
106 ESCRIPT_DLL_API
107 DataLazy(DataAbstract_ptr left, ES_optype op);
108
109 /**
110 \brief Produce a DataLazy for a binary operation.
111 \param left left operand
112 \param right right operand
113 \param op unary operation to perform.
114 \throws DataException if op is not a binary operation or if left or right cannot be converted to a DataLazy.
115 */
116 ESCRIPT_DLL_API
117 DataLazy(DataAbstract_ptr left, DataAbstract_ptr right, ES_optype op);
118
119 ESCRIPT_DLL_API
120 ~DataLazy();
121
122 /**
123 \brief Evaluate the lazy expression.
124 \return A DataReady with the value of the lazy expresion.
125 */
126 ESCRIPT_DLL_API
127 DataReady_ptr
128 resolve();
129
130 ESCRIPT_DLL_API
131 std::string
132 toString() const;
133
134 ESCRIPT_DLL_API
135 DataAbstract*
136 deepCopy();
137
138
139 /**
140 \brief
141 Return the number of doubles that would be stored for this Data object if it were resolved.
142 */
143 ESCRIPT_DLL_API
144 ValueType::size_type
145 getLength() const;
146
147
148 ESCRIPT_DLL_API
149 DataAbstract*
150 getSlice(const DataTypes::RegionType& region) const;
151
152
153 DataTypes::ValueType::size_type
154 getPointOffset(int sampleNo,
155 int dataPointNo) const;
156
157
158 /**
159 \return the number of samples which need to be stored to evaluate the expression.
160 */
161 ESCRIPT_DLL_API
162 int
163 getBuffsRequired() const;
164
165 /**
166 \brief Produces an IDENTITY DataLazy containing zero.
167 The result will have the same shape and functionspace as before.
168 */
169 ESCRIPT_DLL_API
170 virtual void
171 setToZero();
172
173 private:
174 DataReady_ptr m_id; // For IDENTITY nodes, stores a wrapped value.
175 DataLazy_ptr m_left, m_right; // operands for operation.
176 ES_optype m_op; // operation to perform.
177 size_t m_length; // number of values represented by the operation
178
179 int m_buffsRequired; // how many samples are required to evaluate this expression
180 size_t m_samplesize; // number of values required to store a sample
181
182 char m_readytype; // E for expanded, T for tagged, C for constant
183
184
185 /**
186 Does the work for toString.
187 */
188 void
189 intoString(std::ostringstream& oss) const;
190
191 /**
192 \brief Converts the DataLazy into an IDENTITY storing the value of the expression.
193 This method uses the original methods on the Data class to evaluate the expressions.
194 For this reason, it should not be used on DataExpanded instances. (To do so would defeat
195 the purpose of using DataLazy in the first place).
196 */
197 void
198 collapse(); // converts the node into an IDENTITY node
199
200
201 /**
202 \brief Evaluates the expression using methods on Data.
203 This does the work for the collapse method.
204 For reasons of efficiency do not call this method on DataExpanded nodes.
205 */
206 DataReady_ptr
207 collapseToReady();
208
209 /**
210 \brief Compute the value of the expression for the given sample.
211 \return Vector which stores the value of the subexpression for the given sample.
212 \param v A vector to store intermediate results.
213 \param offset Index in v to begin storing results.
214 \param sampleNo Sample number to evaluate.
215 \param roffset (output parameter) the offset in the return vector where the result begins.
216
217 The return value will be an existing vector so do not deallocate it.
218 */
219 const ValueType*
220 resolveSample(ValueType& v, size_t offset ,int sampleNo, size_t& roffset);
221
222 /**
223 \brief Compute the value of the expression (binary operation) for the given sample.
224 \return Vector which stores the value of the subexpression for the given sample.
225 \param v A vector to store intermediate results.
226 \param offset Index in v to begin storing results.
227 \param sampleNo Sample number to evaluate.
228 \param roffset (output parameter) the offset in the return vector where the result begins.
229
230 The return value will be an existing vector so do not deallocate it.
231 If the result is stored in v it should be stored at the offset given.
232 Everything from offset to the end of v should be considered available for this method to use.
233 */
234 ValueType*
235 resolveUnary(ValueType& v, size_t offset,int sampleNo, size_t& roffset) const;
236
237 /**
238 \brief Compute the value of the expression (binary operation) for the given sample.
239 \return Vector which stores the value of the subexpression for the given sample.
240 \param v A vector to store intermediate results.
241 \param offset Index in v to begin storing results.
242 \param sampleNo Sample number to evaluate.
243 \param roffset (output parameter) the offset in the return vector where the result begins.
244
245 The return value will be an existing vector so do not deallocate it.
246 If the result is stored in v it should be stored at the offset given.
247 Everything from offset to the end of v should be considered available for this method to use.
248 */
249 ValueType*
250 resolveBinary(ValueType& v, size_t offset,int sampleNo, size_t& roffset) const;
251
252 };
253
254 }
255 #endif

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