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ArrayOpsDiffShapes.h
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1//# ArrayOpsDiffShapes.h: Operations for 2 Arrays with possibly different shapes.
2//# Copyright (C) 2009
3//# Associated Universities, Inc. Washington DC, USA.
4//#
5//# This program is free software; you can redistribute it and/or modify
6//# it under the terms of the GNU General Public License as published by
7//# the Free Software Foundation; either version 2 of the License, or
8//# (at your option) any later version.
9//#
10//# This program is distributed in the hope that it will be useful,
11//# but WITHOUT ANY WARRANTY; without even the implied warranty of
12//# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13//# GNU General Public License for more details.
14//#
15//# You should have received a copy of the GNU General Public License
16//# along with this program; if not, write to the Free Software
17//# Foundation, Inc., 675 Mass 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 CASA_ARRAYOPSDIFFSHAPES_2_H
29#define CASA_ARRAYOPSDIFFSHAPES_2_H
30
31#include "ArrayMath.h"
32#include "ArrayLogical.h"
33#include "IPosition.h"
34
35//# Don't forget a .tcc file is included at the end!
36
37namespace casacore { //# NAMESPACE CASACORE - BEGIN
38
39// <summary>
40// Operations for 2 Arrays with possibly different shapes.
41// </summary>
42// <!-- <reviewed reviewer="UNKNOWN" date="" tests=""> -->
43//
44// <prerequisite>
45// <li> <linkto class=Array>Array</linkto>
46// <li> <linkto>ArrayMath</linkto>
47// </prerequisite>
48//
49// <etymology>
50// This file contains global functions that attempt binary operations with
51// arrays that have possibly differing shapes.
52// </etymology>
53//
54// <synopsis>
55// These functions perform operations on two arrays, left and right, which go
56// chunk by chunk in left and element by element in right, as long as right
57// spans a subspace of left. If left's shape has more dimensions than right's,
58// each entry in right will effectively be replicated as necessary to act on
59// each entry in the corresponding chunk of left.
60// e.g. if left's shape is (256, 256, 1, 4), and right's is (256, 256),
61// left(i, j, 1, l) will be operated on with right(i, j) for i & j from 0 to
62// 255 and l from 0 to 3. Note that right must be either reformable to left's
63// shape (same # of elements) or its shape must equal left's shape "as far as
64// it goes", i.e. where right's dimensions are defined.
65// </synopsis>
66//
67// <example>
68// <srcblock>
69// Array<Complex> a(10, 6);
70// Vector<int> b(10);
71// Array<Complex> c(10, 6);
72//
73// c = binOpExpandR(a, b, std::plus<Complex>());
74// </srcblock>
75// This example sets c(i, j) to a(i, j) + b(i). It checks that either b's
76// shape can be reformed to a's (same # of elements) or that a's shape is the
77// same as b's where b's dimensions are defined.
78// The result of this operation is an Array.
79// </example>
80
81// <group name=OpsDiff_functions>
83// Returns a LogicalArray with elements (at pos) set to (data(pos) ==
84// truthvalue). data is effectively collapsed using anyEQ if necessary to
85// fit desiredform. Throws an exception if that does not work.
86template<typename T, typename Alloc>
87LogicalArray reformedMask(const Array<T, Alloc>& data, const T truthvalue,
88 const IPosition& desiredform);
89
90// Can arrays left and right with respective shapes leftShape and rightShape be
91// used in function(left, right, ...) for the other functions declared here?
92bool rightExpandableToLeft(const IPosition& leftShape, const IPosition& rightShape);
93
94// Apply op elementwise to left and right, replicating elements of right as
95// necessary (see example above). Throws an ArrayConformanceError exception if
96// that cannot be done.
97//
98// Currently assumes that it is the trailing axes of left that right will be
99// replicated along. e.g. if left's shape is (1, 2, 4) and right's is (1, 2),
100// the result will be left(i, j, k) op right(i, j) for all (i, j, k).
101//
102//# template<typename L, typename R, typename BinaryOperator, typename RES>
103//# Array<RES> binOpExpandR(const Array<L>& left, const Array<R>& right,
104//# BinaryOperator op);
105
106// Like binOpExpandR(left, right, res, op), but work on left in place.
107template<typename L, typename AllocL, typename R, typename AllocR, typename BinaryOperator>
108void binOpExpandInPlace(Array<L, AllocL>& left, const Array<R, AllocR>& right, BinaryOperator op);
109
110// </group>
111
112} //#End casa namespace
113
114#include "ArrayOpsDiffShapes.tcc"
115
116#endif
this file contains all the compiler specific defines
Definition mainpage.dox:28
bool rightExpandableToLeft(const IPosition &leftShape, const IPosition &rightShape)
Can arrays left and right with respective shapes leftShape and rightShape be used in function(left,...
LogicalArray reformedMask(const Array< T, Alloc > &data, const T truthvalue, const IPosition &desiredform)
Returns a LogicalArray with elements (at pos) set to (data(pos) == truthvalue).
void binOpExpandInPlace(Array< L, AllocL > &left, const Array< R, AllocR > &right, BinaryOperator op)
Apply op elementwise to left and right, replicating elements of right as necessary (see example above...