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TiledCollapser.h
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1//# TiledCollapser.h: Abstract base class to collapse chunks for LatticeApply
2//# Copyright (C) 1996,1997,1998
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 LATTICES_TILEDCOLLAPSER_H
29#define LATTICES_TILEDCOLLAPSER_H
30
31
32//# Includes
33#include <casacore/casa/aips.h>
34#include <casacore/casa/Arrays/ArrayFwd.h>
35#include <casacore/scimath/Mathematics/NumericTraits.h>
36
37namespace casacore { //# NAMESPACE CASACORE - BEGIN
38
39//# Forward Declarations
40class IPosition;
41
42// <summary>
43// Abstract base class to collapse chunks for LatticeApply
44// </summary>
45
46// <use visibility=export>
47
48// <reviewed reviewer="" date="yyyy/mm/dd" tests="" demos="">
49// </reviewed>
50
51// <prerequisite>
52// <li> <linkto class=LatticeApply>LatticeApply</linkto>
53// </prerequisite>
54
55// <etymology>
56// </etymology>
57
58// <synopsis>
59// This is an abstract base class for the collapsing of chunks to
60// be used in function <src>tiledApply</src>
61// in class <linkto class=LatticeApply>LatticeApply</linkto>.
62// It is meant for cases where an entire line or plane is not needed
63// (e.g. calculation of maximum). If that is needed (e.g. to calculate moment),
64// it is better to use function <src>LatticeApply::lineApply</src>
65// with class <linkto class=LineCollapser>LineCollapser</linkto>.
66// <p>
67// The user has to derive a concrete class from this base class
68// and implement the (pure) virtual functions.
69// <br> The main function is <src>process</src>, which needs to do the
70// calculation.
71// <br> Other functions make it possible to perform an initial check.
72// <p>
73// The class is Doubly templated. Ths first template type
74// is for the data type you are processing. The second type is
75// for what type you want the results of the processing assigned to.
76// For example, if you are computing sums of squares for statistical
77// purposes, you might use higher precision (FLoat->Double) for this.
78// No check is made that the template types are self-consistent.
79// </synopsis>
80
81// <example>
82// <srcblock>
83// </srcblock>
84// </example>
85
86// <motivation>
87// </motivation>
88
89// <todo asof="1997/08/01">
90// <li>
91// </todo>
92
93
94template <class T, class U=T> class TiledCollapser
95{
96public:
97
98// Destructor
99 virtual ~TiledCollapser();
100
101// The init function for a derived class.
102// It can be used to check if <src>nOutPixelsPerCollapse</src>
103// corresponds with the number of pixels produced per collapsed chunk.
104// <br><src>processAxis</src> is the axis of the line being passed
105// to the <src>process</src> function.
106 virtual void init (uInt nOutPixelsPerCollapse) = 0;
107
108// Can the process function in the derived class handle a null mask pointer?
109// If not, LatticeApply ensures that it'll always pass a mask block,
110// even if the lattice does not have a mask (in that case that mask block
111// contains all True values).
112// <br>The default implementation returns False.
113// <br>The function is there to make optimization possible when no masks
114// are involved. On the other side, it allows the casual user to ignore
115// optimization.
116 virtual Bool canHandleNullMask() const;
117
118// Create and initialize the accumulator.
119// The accumulator can be a cube with shape [n1,n2,n3],
120// where <src>n2</src> is equal to <src>nOutPixelsPerCollapse</src>.
121// However, one can also use several matrices as accumulator.
122// <br> The data type of the accumulator can be any. E.g. when
123// accumulating Float lattices, the accumulator could be of
124// type Double to have enough precision.
125// <br>In the <src>endAccumulator</src> function the accumulator
126// data has to be copied into an Array object with the correct
127// shape and data type.
128 virtual void initAccumulator (uInt64 n1, uInt64 n3) = 0;
129
130// Collapse the given input data containing (<src>nrval</src> values
131// with an increment of <src>inDataIncr</src> elements).
132// <src>inMask</src> is a Bool block representing a mask with the
133// same nr of values and increment as the input data. If a mask
134// value is False, the corresponding input value is masked off.
135// <br>When function <src>canHandleNullMask</src> returned True,
136// it is possible that <src>inMask</src> is a null pointer indicating
137// that the input has no mask, thus all values are valid.
138// <br>
139// The result(s) have to be stored in the accumulator at the given indices.
140// <br><src>startPos</src> gives the lattice position of the first value.
141// The position of other values can be calculated from index and shape
142// using function <src>toPositionInArray</src> in class
143// <linkto class=IPosition>IPosition</linkto>.
144 virtual void process (uInt accumIndex1, uInt accumIndex3,
145 const T* inData, const Bool* inMask,
146 uInt inDataIncr, uInt inMaskIncr,
147 uInt nrval,
148 const IPosition& startPos,
149 const IPosition& shape) = 0;
150
151// End the accumulator. It should return the accumulator as an
152// Array of datatype U (e.g. double the precision of type T)
153// with the given shape. The accumulator should thereafter be deleted when needed.
154 virtual void endAccumulator (Array<U>& result,
155 Array<Bool>& resultMask,
156 const IPosition& shape) = 0;
157};
158
159
160
161} //# NAMESPACE CASACORE - END
162
163#ifndef CASACORE_NO_AUTO_TEMPLATES
164#include <casacore/lattices/LatticeMath/TiledCollapser.tcc>
165#endif //# CASACORE_NO_AUTO_TEMPLATES
166#endif
virtual void initAccumulator(uInt64 n1, uInt64 n3)=0
Create and initialize the accumulator.
virtual void endAccumulator(Array< U > &result, Array< Bool > &resultMask, const IPosition &shape)=0
End the accumulator.
virtual ~TiledCollapser()
Destructor.
virtual Bool canHandleNullMask() const
Can the process function in the derived class handle a null mask pointer? If not, LatticeApply ensure...
virtual void init(uInt nOutPixelsPerCollapse)=0
The init function for a derived class.
virtual void process(uInt accumIndex1, uInt accumIndex3, const T *inData, const Bool *inMask, uInt inDataIncr, uInt inMaskIncr, uInt nrval, const IPosition &startPos, const IPosition &shape)=0
Collapse the given input data containing (nrval values with an increment of inDataIncr elements).
this file contains all the compiler specific defines
Definition mainpage.dox:28
unsigned int uInt
Definition aipstype.h:51
TableExprNode shape(const TableExprNode &array)
Function operating on any scalar or array resulting in a Double array containing the shape.
Definition ExprNode.h:1987
bool Bool
Define the standard types used by Casacore.
Definition aipstype.h:42
unsigned long long uInt64
Definition aipsxtype.h:39