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ScaledComplexData.h
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1//# ScaledComplexData.h: Templated virtual column engine to scale a complex table array
2//# Copyright (C) 1999,2000,2001
3//# Associated Universities, Inc. Washington DC, USA.
4//#
5//# This library is free software; you can redistribute it and/or modify it
6//# under the terms of the GNU Library General Public License as published by
7//# the Free Software Foundation; either version 2 of the License, or (at your
8//# option) any later version.
9//#
10//# This library is distributed in the hope that it will be useful, but WITHOUT
11//# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12//# FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public
13//# License for more details.
14//#
15//# You should have received a copy of the GNU Library General Public License
16//# along with this library; if not, write to the Free Software Foundation,
17//# Inc., 675 Massachusetts Ave, Cambridge, MA 02139, USA.
18//#
19//# Correspondence concerning AIPS++ should be addressed as follows:
20//# Internet email: aips2-request@nrao.edu.
21//# Postal address: AIPS++ Project Office
22//# National Radio Astronomy Observatory
23//# 520 Edgemont Road
24//# Charlottesville, VA 22903-2475 USA
25//#
26//# $Id$
27
28#ifndef TABLES_SCALEDCOMPLEXDATA_H
29#define TABLES_SCALEDCOMPLEXDATA_H
30
31
32//# Includes
33#include <casacore/casa/aips.h>
34#include <casacore/tables/DataMan/BaseMappedArrayEngine.h>
35
36namespace casacore { //# NAMESPACE CASACORE - BEGIN
37
38//# Forward Declarations
39template<class T> class ScalarColumn;
40
41
42// <summary>
43// Templated virtual column engine to scale a complex table array
44// </summary>
45
46// <use visibility=export>
47
48// <reviewed reviewer="Gareth Hunt" date="94Nov17" tests="">
49// </reviewed>
50
51// <prerequisite>
52//# Classes you should understand before using this one.
53// <li> VirtualColumnEngine
54// <li> VirtualArrayColumn
55// </prerequisite>
56
57// <synopsis>
58// ScaledComplexData is a virtual column engine which scales an array
59// of a complex type to 2 values of another type (to save disk storage).
60// For example, <src>ScaledComplexData<Complex,Short></src> resembles the
61// classic AIPS compress method which scales the data from float to short.
62// The (complex) scale factor and offset value can be given in two ways:
63// <ul>
64// <li> As a fixed value which is used for all arrays in the column.
65// <li> As the name of a column. In this way each array in a
66// column can have its own scale and offset value.
67// The scale and offset value in a row must be put before
68// the array is put and should not be changed anymore.
69// </ul>
70// It is also possible to have a variable scale factor with a fixed offset
71// value.
72// As in FITS the scale and offset values are used as:
73// <br><src> True_value = Stored_value * scale + offset; </src>
74//
75// An engine object should be used for one column only, because the stored
76// column name is part of the engine. If it would be used for more than
77// one column, they would all share the same stored column.
78// When the engine is bound to a column, it is checked if the name
79// of that column matches the given virtual column name.
80//
81// The engine can be used for a column containing any kind of array
82// (thus direct or indirect, fixed or variable shaped)) as long as the
83// virtual array can be stored in the stored array. Thus a fixed shaped
84// virtual can use a variable shaped stored, but not vice versa.
85// A fixed shape indirect virtual can use a stored with direct arrays.
86//
87// This class can also serve as an example of how to implement
88// a virtual column engine.
89// </synopsis>
90
91// <motivation>
92// This class allows to store data in a smaller representation.
93// It is needed to resemble the classic AIPS compress option.
94// It adds the scale and offset value on a per row basis.
95//
96// Because the engine can serve only one column, it was possible to
97// combine the engine and the column functionality in one class.
98// This has been achieved using multiple inheritance.
99// The advantage of this is that only one templated class is used,
100// so less template instantiations are needed.
101//
102// Class ScaledArrayEngine could not be used, because complex integer
103// types are not supported in the tabe system.
104// </motivation>
105
106// <example>
107// <srcblock>
108// // Create the table description and 2 columns with indirect arrays in it.
109// // The Int column will be stored, while the double will be
110// // used as virtual.
111// TableDesc tableDesc ("", TableDesc::Scratch);
112// tableDesc.addColumn (ArrayColumnDesc<Short> ("storedArray"));
113// tableDesc.addColumn (ArrayColumnDesc<Complex> ("virtualArray"));
114//
115// // Create a new table using the table description.
116// SetupNewTable newtab (tableDesc, "tab.data", Table::New);
117//
118// // Create the array scaling engine to scale from double to Int
119// // and bind it to the double column.
120// // Create the table.
121// ScaledComplexData<Complex,Short> scalingEngine("virtualArray",
122// "storedArray", 10);
123// newtab.bindColumn ("virtualArray", scalingEngine);
124// Table table (newtab);
125//
126// // Store a 2-D array (with dim. 3,4) into each row of the column.
127// // The shape of each array in the column is implicitly set by the put
128// // function. This will also set the shape of the underlying Int array
129// // (as a 3-D array with shape 2,3,4).
130// ArrayColumn data (table, "virtualArray");
131// Array<DComplex> someArray(IPosition(2,3,4));
132// someArray = 0;
133// for (rownr_t i=0, i<10; i++) { // table will have 10 rows
134// table.addRow();
135// data.put (i, someArray)
136// }
137// </srcblock>
138// </example>
139
140// <templating arg=VirtualType>
141// <li> only complex data types
142// </templating>
143// <templating arg=StoredType>
144// <li> only built-in numerics data types
145// </templating>
146
147template<class VirtualType, class StoredType>
148class ScaledComplexData : public BaseMappedArrayEngine<VirtualType, StoredType>
149{
150 //# Make members of parent class known.
151public:
152 using BaseMappedArrayEngine<VirtualType,StoredType>::virtualName;
153protected:
154 using BaseMappedArrayEngine<VirtualType,StoredType>::storedName;
155 using BaseMappedArrayEngine<VirtualType,StoredType>::table;
156 using BaseMappedArrayEngine<VirtualType,StoredType>::column;
157 using BaseMappedArrayEngine<VirtualType,StoredType>::setNames;
158
159public:
160 // Construct an engine to scale all arrays in a column with
161 // the given offset and scale factor.
162 // StoredColumnName is the name of the column where the scaled
163 // data will be put and must have data type StoredType.
164 // The virtual column using this engine must have data type VirtualType.
165 ScaledComplexData (const String& virtualColumnName,
166 const String& storedColumnName,
167 VirtualType scale,
168 VirtualType offset = 0);
169
170 // Construct an engine to scale the arrays in a column.
171 // The scale and offset values are taken from a column with
172 // the given names. In that way each array has its own scale factor
173 // and offset value.
174 // An exception is thrown if these columns do not exist.
175 // VirtualColumnName is the name of the virtual column and is used to
176 // check if the engine gets bound to the correct column.
177 // StoredColumnName is the name of the column where the scaled
178 // data will be put and must have data type StoredType.
179 // The virtual column using this engine must have data type VirtualType.
180 // <group>
181 ScaledComplexData (const String& virtualColumnName,
182 const String& storedColumnName,
183 const String& scaleColumnName,
184 VirtualType offset = 0);
185 ScaledComplexData (const String& virtualColumnName,
186 const String& storedColumnName,
187 const String& scaleColumnName,
188 const String& offsetColumnName);
189 // </group>
190
191 // Construct from a record specification as created by getmanagerSpec().
193
194 // Destructor is mandatory.
196
197 // Return the type name of the engine (i.e. its class name).
199
200 // Record a record containing data manager specifications.
201 virtual Record dataManagerSpec() const;
202
203 // Return the name of the class.
204 // This includes the names of the template arguments.
206
207 // Register the class name and the static makeObject "constructor".
208 // This will make the engine known to the table system.
209 // The automatically invoked registration function in DataManReg.cc
210 // contains ScaledComplexData<double,Int>.
211 // Any other instantiation of this class must be registered "manually"
212 // (or added to DataManReg.cc).
213 static void registerClass();
214
215private:
216 // The default constructor is required for reconstruction of the
217 // engine when a table is read back.
219
220 // Copy constructor is only used by clone().
221 // (so it is made private).
223
224 // Assignment is not needed and therefore forbidden
225 // (so it is made private and not implemented).
228
229 // Clone the engine object.
230 virtual DataManager* clone() const;
231
232 // Initialize the object for a new table.
233 // It defines the keywords containing the engine parameters.
234 virtual void create64 (rownr_t initialNrrow);
235
236 // Preparing consists of setting the writable switch and
237 // adding the initial number of rows in case of create.
238 // Furthermore it reads the keywords containing the engine parameters.
239 virtual void prepare();
240
241 // Set the shape of the FixedShape arrays in the column.
242 // This function only gets called if the column has FixedShape arrays.
243 // The shape gets saved and used to set the shape of the arrays
244 // in the stored in case the stored has non-FixedShape arrays.
245 virtual void setShapeColumn (const IPosition& shape);
246
247 // Define the shape of the array in the given row.
248 // When the shape of the (underlying) stored array has already been
249 // defined, it checks whether its latter dimensions match the given
250 // virtual shape. When matching, nothing will be done.
251 // When mismatching or when the stored shape has not been defined
252 // yet, the stored shape will be defined from the virtual shape and
253 // the virtual element shape.
254 // E.g. in case of a StokesVector a virtual shape of (512,512)
255 // results in a stored shape of (4,512,512).
256 virtual void setShape (rownr_t rownr, const IPosition& shape);
257
258 // Get the dimensionality of the array in the given row.
259 virtual uInt ndim (rownr_t rownr);
260
261 // Get the shape of the array in the given row.
262 // This is done by stripping the first dimension from the shape
263 // of the underlying stored array.
264 virtual IPosition shape (rownr_t rownr);
265
266 // Get an array in the given row.
267 // This will scale and offset from the underlying array.
268 virtual void getArray (rownr_t rownr, Array<VirtualType>& array);
269
270 // Put an array in the given row.
271 // This will scale and offset to the underlying array.
272 virtual void putArray (rownr_t rownr, const Array<VirtualType>& array);
273
274 // Get a section of the array in the given row.
275 // This will scale and offset from the underlying array.
276 virtual void getSlice (rownr_t rownr, const Slicer& slicer,
278
279 // Put into a section of the array in the given row.
280 // This will scale and offset to the underlying array.
281 virtual void putSlice (rownr_t rownr, const Slicer& slicer,
283
284 // Get an entire column.
285 // This will scale and offset from the underlying array.
287
288 // Put an entire column.
289 // This will scale and offset to the underlying array.
291
292 // Get some array values in the column.
293 // This will scale and offset from the underlying array.
294 virtual void getArrayColumnCells (const RefRows& rownrs,
295 Array<VirtualType>& data);
296
297 // Put some array values in the column.
298 // This will scale and offset to the underlying array.
299 virtual void putArrayColumnCells (const RefRows& rownrs,
300 const Array<VirtualType>& data);
301
302 // Get a section of all arrays in the column.
303 // This will scale and offset from the underlying array.
304 virtual void getColumnSlice (const Slicer& slicer,
306
307 // Put a section of all arrays in the column.
308 // This will scale and offset to the underlying array.
309 virtual void putColumnSlice (const Slicer& slicer,
311
312 // Get a section of some arrays in the column.
313 // This will scale and offset from the underlying array.
314 virtual void getColumnSliceCells (const RefRows& rownrs,
315 const Slicer& slicer,
316 Array<VirtualType>& data);
317
318 // Put into a section of some arrays in the column.
319 // This will scale and offset to the underlying array.
320 virtual void putColumnSliceCells (const RefRows& rownrs,
321 const Slicer& slicer,
322 const Array<VirtualType>& data);
323
324 // Scale and/or offset stored to array.
325 // This is meant when reading an array from the stored column.
326 // It optimizes for scale=1 and/or offset=0.
327 void scaleOnGet (VirtualType scale, VirtualType offset,
329 const Array<StoredType>& stored);
330
331 // Scale and/or offset array to stored.
332 // This is meant when writing an array into the stored column.
333 // It optimizes for scale=1 and/or offset=0.
334 void scaleOnPut (VirtualType scale, VirtualType offset,
336 Array<StoredType>& stored);
337
338 // Scale and/or offset stored to array for the entire column.
339 // When the scale and offset are fixed, it will do the entire array.
340 // Otherwise it iterates through the array and applies the scale
341 // and offset per row.
343 const Array<StoredType>& stored);
344
345 // Scale and/or offset array to stored for the entire column.
346 // When the scale and offset are fixed, it will do the entire array.
347 // Otherwise it iterates through the array and applies the scale
348 // and offset per row.
350 Array<StoredType>& stored);
351
352 // Scale and/or offset stored to array for some cells in the column.
353 // When the scale and offset are fixed, it will do the entire array.
354 // Otherwise it iterates through the array and applies the scale
355 // and offset per row.
357 const Array<StoredType>& stored,
358 const RefRows& rownrs);
359
360 // Scale and/or offset array to stored for some cells in the column.
361 // When the scale and offset are fixed, it will do the entire array.
362 // Otherwise it iterates through the array and applies the scale
363 // and offset per row.
365 Array<StoredType>& stored,
366 const RefRows& rownrs);
367
368 // Determine the shape of an array in the stored column.
369 IPosition storedShape (const IPosition& virtualShape) const
370 { return IPosition(1,2).concatenate (virtualShape); }
371
372 // Convert the Slicer for a virtual to a Slicer for the stored.
373 Slicer storedSlicer (const Slicer& virtualSlicer) const;
374
375 //# Now define the data members.
376 String scaleName_p; //# name of scale column
377 String offsetName_p; //# name of offset column
378 VirtualType scale_p; //# scale factor
379 VirtualType offset_p; //# offset value
380 Bool fixedScale_p; //# scale is a fixed column
381 Bool fixedOffset_p; //# offset is a fixed column
382 ScalarColumn<VirtualType>* scaleColumn_p; //# column with scale value
383 ScalarColumn<VirtualType>* offsetColumn_p; //# column with offset value
384
385 // Get the scale value for this row.
386 VirtualType getScale (rownr_t rownr);
387
388 // Get the offset value for this row.
389 VirtualType getOffset (rownr_t rownr);
390
391public:
392 // Define the "constructor" to construct this engine when a
393 // table is read back.
394 // This "constructor" has to be registered by the user of the engine.
395 // If the engine is commonly used, its registration can be added
396 // to the registerAllCtor function in DataManReg.cc.
397 // That function gets automatically invoked by the table system.
399 const Record& spec);
400};
401
402
403
404} //# NAMESPACE CASACORE - END
405
406#ifndef CASACORE_NO_AUTO_TEMPLATES
407#include <casacore/tables/DataMan/ScaledComplexData.tcc>
408#endif //# CASACORE_NO_AUTO_TEMPLATES
409#endif
ArrayColumn< StoredType > & column()
Give access to the stored column.
void setNames(const String &virtualName, const String &storedName)
Set the virtual and stored column name.
const String & storedName() const
Get the stored column name.
const String & virtualName() const
Get the virtual column name.
Abstract base class for a data manager.
Table & table() const
Get the table this object is associated with.
IPosition concatenate(const IPosition &other) const
Return an IPosition as the concetanation of this and another IPosition.
void scaleColumnOnPut(const Array< VirtualType > &array, Array< StoredType > &stored)
Scale and/or offset array to stored for the entire column.
IPosition storedShape(const IPosition &virtualShape) const
Determine the shape of an array in the stored column.
virtual IPosition shape(rownr_t rownr)
Get the shape of the array in the given row.
ScaledComplexData(const Record &spec)
Construct from a record specification as created by getmanagerSpec().
void scaleColumnOnGet(Array< VirtualType > &array, const Array< StoredType > &stored)
Scale and/or offset stored to array for the entire column.
virtual void putColumnSliceCells(const RefRows &rownrs, const Slicer &slicer, const Array< VirtualType > &data)
Put into a section of some arrays in the column.
virtual DataManager * clone() const
Clone the engine object.
void scaleOnPut(VirtualType scale, VirtualType offset, const Array< VirtualType > &array, Array< StoredType > &stored)
Scale and/or offset array to stored.
virtual void putSlice(rownr_t rownr, const Slicer &slicer, const Array< VirtualType > &array)
Put into a section of the array in the given row.
void scaleOnGet(VirtualType scale, VirtualType offset, Array< VirtualType > &array, const Array< StoredType > &stored)
Scale and/or offset stored to array.
static DataManager * makeObject(const String &dataManagerType, const Record &spec)
Define the "constructor" to construct this engine when a table is read back.
virtual void setShape(rownr_t rownr, const IPosition &shape)
Define the shape of the array in the given row.
virtual void getSlice(rownr_t rownr, const Slicer &slicer, Array< VirtualType > &array)
Get a section of the array in the given row.
virtual void create64(rownr_t initialNrrow)
Initialize the object for a new table.
virtual void putColumnSlice(const Slicer &slicer, const Array< VirtualType > &array)
Put a section of all arrays in the column.
ScaledComplexData(const String &virtualColumnName, const String &storedColumnName, const String &scaleColumnName, const String &offsetColumnName)
virtual void getArrayColumn(Array< VirtualType > &array)
Get an entire column.
static String className()
Return the name of the class.
ScaledComplexData(const ScaledComplexData< VirtualType, StoredType > &)
Copy constructor is only used by clone().
virtual void setShapeColumn(const IPosition &shape)
Set the shape of the FixedShape arrays in the column.
virtual void putArray(rownr_t rownr, const Array< VirtualType > &array)
Put an array in the given row.
Slicer storedSlicer(const Slicer &virtualSlicer) const
Convert the Slicer for a virtual to a Slicer for the stored.
virtual uInt ndim(rownr_t rownr)
Get the dimensionality of the array in the given row.
void scaleCellsOnGet(Array< VirtualType > &array, const Array< StoredType > &stored, const RefRows &rownrs)
Scale and/or offset stored to array for some cells in the column.
virtual void prepare()
Preparing consists of setting the writable switch and adding the initial number of rows in case of cr...
ScaledComplexData(const String &virtualColumnName, const String &storedColumnName, VirtualType scale, VirtualType offset=0)
Construct an engine to scale all arrays in a column with the given offset and scale factor.
String dataManagerType() const
Return the type name of the engine (i.e.
virtual void getColumnSliceCells(const RefRows &rownrs, const Slicer &slicer, Array< VirtualType > &data)
Get a section of some arrays in the column.
ScalarColumn< VirtualType > * offsetColumn_p
virtual void getColumnSlice(const Slicer &slicer, Array< VirtualType > &array)
Get a section of all arrays in the column.
virtual void putArrayColumnCells(const RefRows &rownrs, const Array< VirtualType > &data)
Put some array values in the column.
ScaledComplexData(const String &virtualColumnName, const String &storedColumnName, const String &scaleColumnName, VirtualType offset=0)
Construct an engine to scale the arrays in a column.
virtual void getArrayColumnCells(const RefRows &rownrs, Array< VirtualType > &data)
Get some array values in the column.
VirtualType getScale(rownr_t rownr)
Get the scale value for this row.
ScalarColumn< VirtualType > * scaleColumn_p
VirtualType getOffset(rownr_t rownr)
Get the offset value for this row.
static void registerClass()
Register the class name and the static makeObject "constructor".
virtual void getArray(rownr_t rownr, Array< VirtualType > &array)
Get an array in the given row.
~ScaledComplexData()
Destructor is mandatory.
virtual Record dataManagerSpec() const
Record a record containing data manager specifications.
virtual void putArrayColumn(const Array< VirtualType > &array)
Put an entire column.
void scaleCellsOnPut(const Array< VirtualType > &array, Array< StoredType > &stored, const RefRows &rownrs)
Scale and/or offset array to stored for some cells in the column.
ScaledComplexData()
The default constructor is required for reconstruction of the engine when a table is read back.
String: the storage and methods of handling collections of characters.
Definition String.h:225
this file contains all the compiler specific defines
Definition mainpage.dox:28
unsigned int uInt
Definition aipstype.h:51
TableExprNode array(const TableExprNode &values, const TableExprNodeSet &shape)
Create an array of the given shape and fill it with the values.
Definition ExprNode.h:1929
bool Bool
Define the standard types used by Casacore.
Definition aipstype.h:42
uInt64 rownr_t
Define the type of a row number in a table.
Definition aipsxtype.h:46