00001 //# IDIndex.h: this defines IDIndex, which maps one indexing system into another 00002 //# Copyright (C) 2000,2001 00003 //# Associated Universities, Inc. Washington DC, USA. 00004 //# 00005 //# This library is free software; you can redistribute it and/or modify it 00006 //# under the terms of the GNU Library General Public License as published by 00007 //# the Free Software Foundation; either version 2 of the License, or (at your 00008 //# option) any later version. 00009 //# 00010 //# This library is distributed in the hope that it will be useful, but WITHOUT 00011 //# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 00012 //# FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public 00013 //# License for more details. 00014 //# 00015 //# You should have received a copy of the GNU Library General Public License 00016 //# along with this library; if not, write to the Free Software Foundation, 00017 //# Inc., 675 Massachusetts Ave, Cambridge, MA 02139, USA. 00018 //# 00019 //# Correspondence concerning AIPS++ should be addressed as follows: 00020 //# Internet email: aips2-request@nrao.edu. 00021 //# Postal address: AIPS++ Project Office 00022 //# National Radio Astronomy Observatory 00023 //# 520 Edgemont Road 00024 //# Charlottesville, VA 22903-2475 USA 00025 //# 00026 //# 00027 //# $Id: IDIndex.h,v 1.2 2009/09/03 23:28:32 pteuben Exp $ 00028 00029 #ifndef BIMA_IDINDEX_H 00030 #define BIMA_IDINDEX_H 00031 00032 #include <casa/Containers/SimOrdMap.h> 00033 00034 #include <casa/namespace.h> 00035 // <summary> 00036 // a simple mapping from one indexing system to another 00037 // </summary> 00038 // 00039 // <use visibility=export> 00040 // 00041 // <reviewed reviewer="" date="yyyy/mm/dd" tests="" demos=""> 00042 // </reviewed> 00043 // 00044 // <etymology> 00045 // This class is puts an index on an ordered list of IDs. 00046 // </etymology> 00047 // 00048 // <synopsis> 00049 // Suppose that you have a list of things accessed via an index (i.e. an 00050 // integer ID), say spectral windows. Suppose further you want to map them 00051 // into some other index system, perhaps because you are reordering them. 00052 // This simple class can keep track of the mapping between the two systems. <p> 00053 // 00054 // The mapping is set up through sequenced calls to the <src>add()</src> 00055 // function, to which indices from the "input" system are passed. The order 00056 // that the indices are passed indicate their order in the output system. 00057 // One can then map to the output system by passing the input index to the 00058 // () operator. <p> 00059 // 00060 // One sets the index that the first input index will be mapped to via the 00061 // constructor, allowing one to map, for example, {1, 3, 2} into {4, 5, 6}. 00062 // </synopsis> 00063 // 00064 // <example> 00065 // Suppose only selected windows will be written out. Here's how we can keep 00066 // track of the mapping: 00067 // <srcblock> 00068 // IDIndex idx(1); // the first index mapped into is 1 00069 // for(Int i=0; i < nspect; i++) { 00070 // if (windowSelected(i)) idx.add(i) // 0 -> 1 if selected 00071 // } 00072 // 00073 // // which output window is the second window mapped to? 00074 // Int outwin = idx(2); // outwin = -1 if not selected 00075 // </srcblock> 00076 // </example> 00077 // 00078 // <motivation> 00079 // The MirFiller class needs to keep track of which Miriad windows get mapped 00080 // into which MS spectral windows. Since the user can select which windows 00081 // will be loaded, its not easy to predict otherwise how the windows will get 00082 // mapped. Furthermore, Miriad wideband channels are loaded as seperate 00083 // windows in the output MS, thus the mapping from channel number to window 00084 // will not necessarily start with 0. 00085 // </motivation> 00086 00087 class IDIndex { 00088 private: 00089 Int offset; 00090 SimpleOrderedMap<Int, Int> idmap; 00091 public: 00092 // create an ID set. <src>first</src> is the output index that the first 00093 // input ID passed to <src>add()</src> will be mapped to. 00094 //PJT 00095 // explicit IDIndex(Int first=0); 00096 IDIndex(Int first=0); 00097 00098 // create a copy of another IDIndex 00099 IDIndex(IDIndex& that); 00100 00101 // destroy this index 00102 ~IDIndex(); 00103 00104 // add an ID to the set; 00105 void add(Int id) { idmap.define(id, next()); } 00106 00107 // return the ID mapping 00108 Int operator()(Int id) { return idmap(id); } 00109 00110 // return the output index that the first input ID is mapped to. This is the 00111 // value returned by operator(0); 00112 Int first() { return offset; } 00113 00114 // return the next index to be mapped to when add is next called. 00115 Int next() { return offset+idmap.ndefined(); } 00116 00117 // return the number of input IDs mapped 00118 Int size() { return idmap.ndefined(); } 00119 00120 // remove all ID mappings. This returns the index to its state just 00121 // after construction. 00122 void clear() { idmap.clear(); } 00123 }; 00124 00125 00126 00127 #endif 00128 00129