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1 : //# GridBoth.h: Definition for GridBoth
2 : //# Copyright (C) 1996,1997,1998,1999,2000,2001,2002
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 adressed as follows:
20 : //# Internet email: casa-feedback@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 : //#
27 : //# $Id$
28 :
29 : #ifndef SYNTHESIS_GRIDBOTH_H
30 : #define SYNTHESIS_GRIDBOTH_H
31 :
32 : #include <synthesis/TransformMachines/GridFT.h>
33 : #include <synthesis/MeasurementComponents/SDGrid.h>
34 :
35 : namespace casacore{
36 :
37 : template<class T> class TempImage;
38 : }
39 :
40 : namespace casa { //# NAMESPACE CASA - BEGIN
41 :
42 : // <summary> An FTMachine for Gridding Single Dish data
43 : // </summary>
44 :
45 : // <use visibility=export>
46 :
47 : // <reviewed reviewer="" date="" tests="" demos="">
48 :
49 : // <prerequisite>
50 : // <li> <linkto class=FTMachine>FTMachine</linkto> module
51 : // <li> <linkto class=SkyEquation>SkyEquation</linkto> module
52 : // <li> <linkto class=VisBuffer>VisBuffer</linkto> module
53 : // </prerequisite>
54 : //
55 : // <etymology>
56 : // FTMachine is a Machine for Fourier Transforms. GridBoth does
57 : // Single Dish gridding in a similar way
58 : // </etymology>
59 : //
60 : // <synopsis>
61 : // The <linkto class=SkyEquation>SkyEquation</linkto> needs to be able
62 : // to perform Fourier transforms on visibility data and to grid
63 : // single dish data.
64 : // GridBoth allows efficient Single Dish processing using a
65 : // <linkto class=VisBuffer>VisBuffer</linkto> which encapsulates
66 : // a chunk of visibility (typically all baselines for one time)
67 : // together with all the information needed for processing
68 : // (e.g. direction coordinates).
69 : //
70 : // Gridding and degridding in GridBoth are performed using a
71 : // novel sort-less algorithm. In this approach, the gridded plane is
72 : // divided into small patches, a cache of which is maintained in memory
73 : // using a general-purpose <linkto class=casacore::LatticeCache>LatticeCache</linkto> class. As the (time-sorted)
74 : // visibility data move around slowly in the image plane, patches are
75 : // swapped in and out as necessary. Thus, optimally, one would keep at
76 : // least one patch per scan line of data.
77 : //
78 : // A grid cache is defined on construction. If the gridded image plane is smaller
79 : // than this, it is kept entirely in memory and all gridding and
80 : // degridding is done entirely in memory. Otherwise a cache of tiles is
81 : // kept an paged in and out as necessary. Optimally the cache should be
82 : // big enough to hold all polarizations and frequencies for one
83 : // complete scan line.
84 : // The paging rate will then be small. As the cache size is
85 : // reduced below this critical value, paging increases. The algorithm will
86 : // work for only one patch but it will be very slow!
87 : //
88 : // The gridding and degridding steps are implemented in Fortran
89 : // for speed. In gridding, the visibilities are added onto the
90 : // grid points in the neighborhood using a weighting function.
91 : // In degridding, the value is derived by a weight summ of the
92 : // same points, using the same weighting function.
93 : // </synopsis>
94 : //
95 : // <example>
96 : // See the example for <linkto class=SkyModel>SkyModel</linkto>.
97 : // </example>
98 : //
99 : // <motivation>
100 : // Define an interface to allow efficient processing of chunks of
101 : // visibility data
102 : // </motivation>
103 : //
104 : // <todo asof="97/10/01">
105 : // <ul> Deal with large VLA spectral line case
106 : // </todo>
107 :
108 :
109 : class GridBoth : public FTMachine {
110 : public:
111 :
112 : // Constructor: cachesize is the size of the cache in words
113 : // (e.g. a few million is a good number), tilesize is the
114 : // size of the tile used in gridding (cannot be less than
115 : // 12, 16 works in most cases), and convType is the type of
116 : // gridding used (SF is prolate spheriodal wavefunction,
117 : // and BOX is plain box-car summation). mLocation is
118 : // the position to be used in some phase rotations. If
119 : // mTangent is specified then the uvw rotation is done for
120 : // that location iso the image center.
121 : // <group>
122 : GridBoth(SkyJones& sj, casacore::Long cachesize, casacore::Int tilesize,
123 : casacore::String sdConvType="BOX",
124 : casacore::String synConvType="SF",
125 : casacore::Float padding=1.0,
126 : casacore::Float sdScale=1.0,
127 : casacore::Float sdWeight=1.0);
128 : GridBoth(SkyJones& sj, casacore::Long cachesize, casacore::Int tilesize,
129 : casacore::MPosition mLocation,
130 : casacore::String sdConvType="BOX",
131 : casacore::String synConvType="SF",
132 : casacore::Float padding=1.0,
133 : casacore::Float sdScale=1.0,
134 : casacore::Float sdWeight=1.0);
135 : GridBoth(SkyJones& sj, casacore::Long cachesize, casacore::Int tilesize,
136 : casacore::MPosition mLocation, casacore::MDirection mTangent,
137 : casacore::String sdConvType="BOX",
138 : casacore::String synConvType="SF",
139 : casacore::Float padding=1.0,
140 : casacore::Float sdScale=1.0,
141 : casacore::Float sdWeight=1.0);
142 : // </group>
143 :
144 : // Copy constructor
145 : GridBoth(const GridBoth &other);
146 :
147 : // Assignment operator
148 : GridBoth &operator=(const GridBoth &other);
149 :
150 : ~GridBoth();
151 :
152 : // Construct from a casacore::Record containing the GridFT state
153 : GridBoth(const casacore::RecordInterface& stateRec);
154 :
155 : // Initialize transform to Visibility plane using the image
156 : // as a template. The image is loaded and Fourier transformed.
157 : void initializeToVis(casacore::ImageInterface<casacore::Complex>& image,
158 : const VisBuffer& vb);
159 :
160 : // Finalize transform to Visibility plane: flushes the image
161 : // cache and shows statistics if it is being used.
162 : void finalizeToVis();
163 :
164 : // Initialize transform to Sky plane: initializes the image
165 : void initializeToSky(casacore::ImageInterface<casacore::Complex>& image, casacore::Matrix<casacore::Float>& weight,
166 : const VisBuffer& vb);
167 :
168 : // Finalize transform to Sky plane: flushes the image
169 : // cache and shows statistics if it is being used. DOES NOT
170 : // DO THE FINAL TRANSFORM!
171 : void finalizeToSky();
172 :
173 : // Get actual coherence from grid by degridding
174 : void get(VisBuffer& vb, casacore::Int row=-1);
175 :
176 : // Put coherence to grid by gridding.
177 : void put(const VisBuffer& vb, casacore::Int row=-1, casacore::Bool dopsf=false,
178 : FTMachine::Type type=FTMachine::OBSERVED);
179 :
180 : // Get the final image: do the Fourier transform and
181 : // grid-correct, then optionally normalize by the summed weights
182 : casacore::ImageInterface<casacore::Complex>& getImage(casacore::Matrix<casacore::Float>&, casacore::Bool normalize=true);
183 0 : virtual void normalizeImage(casacore::Lattice<casacore::Complex>& /*skyImage*/,
184 : const casacore::Matrix<casacore::Double>& /*sumOfWts*/,
185 : casacore::Lattice<casacore::Float>& /*sensitivityImage*/,
186 : casacore::Bool /*fftNorm*/)
187 0 : {throw(casacore::AipsError("GridBoth::normalizeImage() called"));}
188 :
189 : // Get the final weights image
190 : void getWeightImage(casacore::ImageInterface<casacore::Float>&, casacore::Matrix<casacore::Float>&);
191 :
192 : // Save and restore the GridFT to and from a record
193 : virtual casacore::Bool toRecord(casacore::String& error, casacore::RecordInterface& outRec,
194 : casacore::Bool withImage=false, const casacore::String diskimage="");
195 : virtual casacore::Bool fromRecord(casacore::String& error, const casacore::RecordInterface& inRec);
196 :
197 : // Has this operator changed since the last application?
198 : virtual casacore::Bool changed(const VisBuffer& vb);
199 0 : virtual void setMiscInfo(const casacore::Int qualifier){(void)qualifier;};
200 0 : virtual void ComputeResiduals(VisBuffer&/*vb*/, casacore::Bool /*useCorrected*/) {};
201 0 : virtual casacore::String name() const { return "GridBoth";};
202 :
203 : private:
204 :
205 : FTMachine* synMachine_p; // Synthesis machine
206 : FTMachine* sdMachine_p; // Single Dish machine
207 : FTMachine* lastMachine_p; // Last Machine used
208 :
209 : // Images for Synthesis and SD
210 : casacore::TempImage<casacore::Complex>* sdImage_p;
211 : casacore::TempImage<casacore::Complex>* synImage_p;
212 :
213 : casacore::Float sdScale_p, sdWeight_p;
214 :
215 : void ok();
216 :
217 : void init();
218 :
219 : };
220 :
221 : } //# NAMESPACE CASA - END
222 :
223 : #endif
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