[297] | 1 | //#--------------------------------------------------------------------------- |
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[881] | 2 | //# STLineFinder.h: A class for automated spectral line search |
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[297] | 3 | //#--------------------------------------------------------------------------- |
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| 4 | //# Copyright (C) 2004 |
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| 5 | //# ATNF |
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| 6 | //# |
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| 7 | //# This program is free software; you can redistribute it and/or modify it |
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| 8 | //# under the terms of the GNU General Public License as published by the Free |
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| 9 | //# Software Foundation; either version 2 of the License, or (at your option) |
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| 10 | //# any later version. |
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| 11 | //# |
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| 12 | //# This program is distributed in the hope that it will be useful, but |
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| 13 | //# WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 14 | //# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General |
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| 15 | //# Public License for more details. |
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| 16 | //# |
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| 17 | //# You should have received a copy of the GNU General Public License along |
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| 18 | //# with this program; if not, write to the Free Software Foundation, Inc., |
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| 19 | //# 675 Massachusetts Ave, Cambridge, MA 02139, USA. |
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| 20 | //# |
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| 21 | //# Correspondence concerning this software should be addressed as follows: |
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| 22 | //# Internet email: Malte.Marquarding@csiro.au |
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| 23 | //# Postal address: Malte Marquarding, |
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| 24 | //# Australia Telescope National Facility, |
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| 25 | //# P.O. Box 76, |
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| 26 | //# Epping, NSW, 2121, |
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| 27 | //# AUSTRALIA |
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| 28 | //# |
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[890] | 29 | //# $Id: STLineFinder.h 991 2006-04-05 05:46:01Z vor010 $ |
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[297] | 30 | //#--------------------------------------------------------------------------- |
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[881] | 31 | #ifndef STLINEFINDER_H |
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| 32 | #define STLINEFINDER_H |
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[297] | 33 | |
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| 34 | // STL |
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| 35 | #include <vector> |
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| 36 | #include <list> |
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| 37 | #include <utility> |
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| 38 | #include <exception> |
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| 39 | |
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| 40 | // AIPS++ |
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| 41 | #include <casa/aips.h> |
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| 42 | #include <casa/Exceptions/Error.h> |
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| 43 | #include <casa/Arrays/Vector.h> |
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| 44 | #include <casa/Utilities/Assert.h> |
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| 45 | #include <casa/Utilities/CountedPtr.h> |
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| 46 | |
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| 47 | // ASAP |
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[881] | 48 | #include "ScantableWrapper.h" |
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| 49 | #include "Scantable.h" |
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[297] | 50 | |
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| 51 | namespace asap { |
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| 52 | |
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[352] | 53 | /////////////////////////////////////////////////////////////////////////////// |
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| 54 | // |
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| 55 | // LFLineListOperations - a class incapsulating operations with line lists |
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| 56 | // The LF prefix stands for Line Finder |
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| 57 | // |
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[297] | 58 | |
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[881] | 59 | struct LFLineListOperations { |
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[331] | 60 | // concatenate two lists preserving the order. If two lines appear to |
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[881] | 61 | // be adjacent or have a non-void intersection, they are joined into |
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[343] | 62 | // the new line |
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[344] | 63 | static void addNewSearchResult(const std::list<std::pair<int, int> > |
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| 64 | &newlines, std::list<std::pair<int, int> > &lines_list) |
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[331] | 65 | throw(casa::AipsError); |
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[344] | 66 | |
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| 67 | // extend all line ranges to the point where a value stored in the |
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| 68 | // specified vector changes (e.g. value-mean change its sign) |
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| 69 | // This operation is necessary to include line wings, which are below |
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| 70 | // the detection threshold. If lines becomes adjacent, they are |
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| 71 | // merged together. Any masked channel stops the extension |
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[352] | 72 | static void searchForWings(std::list<std::pair<int, int> > &newlines, |
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| 73 | const casa::Vector<casa::Int> &signs, |
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| 74 | const casa::Vector<casa::Bool> &mask, |
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| 75 | const std::pair<int,int> &edge) |
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[344] | 76 | throw(casa::AipsError); |
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[352] | 77 | protected: |
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[881] | 78 | |
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[343] | 79 | // An auxiliary object function to test whether two lines have a non-void |
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| 80 | // intersection |
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| 81 | class IntersectsWith : public std::unary_function<pair<int,int>, bool> { |
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| 82 | std::pair<int,int> line1; // range of the first line |
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| 83 | // start channel and stop+1 |
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| 84 | public: |
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| 85 | IntersectsWith(const std::pair<int,int> &in_line1); |
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| 86 | // return true if line2 intersects with line1 with at least one |
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| 87 | // common channel, and false otherwise |
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| 88 | bool operator()(const std::pair<int,int> &line2) const throw(); |
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| 89 | }; |
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| 90 | |
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| 91 | // An auxiliary object function to build a union of several lines |
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| 92 | // to account for a possibility of merging the nearby lines |
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| 93 | class BuildUnion { |
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| 94 | std::pair<int,int> temp_line; // range of the first line |
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| 95 | // start channel and stop+1 |
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| 96 | public: |
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| 97 | BuildUnion(const std::pair<int,int> &line1); |
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| 98 | // update temp_line with a union of temp_line and new_line |
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| 99 | // provided there is no gap between the lines |
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| 100 | void operator()(const std::pair<int,int> &new_line) throw(); |
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| 101 | // return the result (temp_line) |
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| 102 | const std::pair<int,int>& result() const throw(); |
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| 103 | }; |
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[881] | 104 | |
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[343] | 105 | // An auxiliary object function to test whether a specified line |
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| 106 | // is at lower spectral channels (to preserve the order in the line list) |
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| 107 | class LaterThan : public std::unary_function<pair<int,int>, bool> { |
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| 108 | std::pair<int,int> line1; // range of the first line |
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| 109 | // start channel and stop+1 |
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| 110 | public: |
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| 111 | LaterThan(const std::pair<int,int> &in_line1); |
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| 112 | |
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| 113 | // return true if line2 should be placed later than line1 |
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| 114 | // in the ordered list (so, it is at greater channel numbers) |
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| 115 | bool operator()(const std::pair<int,int> &line2) const throw(); |
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[881] | 116 | }; |
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| 117 | |
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| 118 | |
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[352] | 119 | }; |
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| 120 | |
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| 121 | // |
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| 122 | /////////////////////////////////////////////////////////////////////////////// |
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| 123 | |
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| 124 | /////////////////////////////////////////////////////////////////////////////// |
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| 125 | // |
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[881] | 126 | // STLineFinder - a class for automated spectral line search |
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[352] | 127 | // |
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| 128 | // |
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| 129 | |
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[881] | 130 | struct STLineFinder : protected LFLineListOperations { |
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| 131 | STLineFinder() throw(); |
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| 132 | virtual ~STLineFinder() throw(casa::AipsError); |
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[352] | 133 | |
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[369] | 134 | // set the parameters controlling algorithm |
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| 135 | // in_threshold a single channel threshold default is sqrt(3), which |
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| 136 | // means together with 3 minimum channels at least 3 sigma |
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| 137 | // detection criterion |
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| 138 | // For bad baseline shape, in_threshold may need to be |
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| 139 | // increased |
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| 140 | // in_min_nchan minimum number of channels above the threshold to report |
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| 141 | // a detection, default is 3 |
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| 142 | // in_avg_limit perform the averaging of no more than in_avg_limit |
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| 143 | // adjacent channels to search for broad lines |
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[881] | 144 | // Default is 8, but for a bad baseline shape this |
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[369] | 145 | // parameter should be decreased (may be even down to a |
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| 146 | // minimum of 1 to disable this option) to avoid |
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| 147 | // confusing of baseline undulations with a real line. |
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[881] | 148 | // Setting a very large value doesn't usually provide |
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| 149 | // valid detections. |
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[369] | 150 | // in_box_size the box size for running mean calculation. Default is |
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| 151 | // 1./5. of the whole spectrum size |
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| 152 | void setOptions(const casa::Float &in_threshold=sqrt(3.), |
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| 153 | const casa::Int &in_min_nchan=3, |
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| 154 | const casa::Int &in_avg_limit=8, |
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| 155 | const casa::Float &in_box_size=0.2) throw(); |
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| 156 | |
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[907] | 157 | // set the scan to work with (in_scan parameter) |
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| 158 | void setScan(const ScantableWrapper &in_scan) throw(casa::AipsError); |
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| 159 | |
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| 160 | // search for spectral lines in a row specified by whichRow |
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| 161 | // in_mask and in_edge parameters control channel rejection |
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| 162 | // if in_edge has zero length, all channels chosen by mask will be used |
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[352] | 163 | // if in_edge has one element only, it represents the number of |
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| 164 | // channels to drop from both sides of the spectrum |
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| 165 | // in_edge is introduced for convinience, although all functionality |
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[881] | 166 | // can be achieved using a spectrum mask only |
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| 167 | // Number of lines found is returned |
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[907] | 168 | int findLines(const std::vector<bool> &in_mask, |
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| 169 | const std::vector<int> &in_edge = std::vector<int>(), |
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| 170 | const casa::uInt &whichRow = 0) throw(casa::AipsError); |
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[352] | 171 | |
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| 172 | // get the mask to mask out all lines that have been found (default) |
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| 173 | // if invert=true, only channels belong to lines will be unmasked |
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| 174 | // Note: all channels originally masked by the input mask (in_mask |
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| 175 | // in setScan) or dropped out by the edge parameter (in_edge |
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| 176 | // in setScan) are still excluded regardless on the invert option |
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| 177 | std::vector<bool> getMask(bool invert=false) const throw(casa::AipsError); |
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| 178 | |
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[370] | 179 | // get range for all lines found. The same units as used in the scan |
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[881] | 180 | // will be returned (e.g. velocity instead of channels). |
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[370] | 181 | std::vector<double> getLineRanges() const throw(casa::AipsError); |
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| 182 | // The same as getLineRanges, but channels are always used to specify |
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| 183 | // the range |
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| 184 | std::vector<int> getLineRangesInChannels() const throw(casa::AipsError); |
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[368] | 185 | protected: |
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| 186 | // auxiliary function to average adjacent channels and update the mask |
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| 187 | // if at least one channel involved in summation is masked, all |
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| 188 | // output channels will be masked. This function works with the |
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| 189 | // spectrum and edge fields of this class, but updates the mask |
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| 190 | // array specified, rather than the field of this class |
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| 191 | // boxsize - a number of adjacent channels to average |
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| 192 | void averageAdjacentChannels(casa::Vector<casa::Bool> &mask2update, |
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| 193 | const casa::Int &boxsize) |
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| 194 | throw(casa::AipsError); |
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[369] | 195 | |
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| 196 | // auxiliary function to fit and subtract a polynomial from the current |
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[890] | 197 | // spectrum. It uses the Fitter class. This action is required before |
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[369] | 198 | // reducing the spectral resolution if the baseline shape is bad |
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| 199 | void subtractBaseline(const casa::Vector<casa::Bool> &temp_mask, |
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| 200 | const casa::Int &order) throw(casa::AipsError); |
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[881] | 201 | |
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[368] | 202 | // an auxiliary function to remove all lines from the list, except the |
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| 203 | // strongest one (by absolute value). If the lines removed are real, |
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[881] | 204 | // they will be find again at the next iteration. This approach |
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| 205 | // increases the number of iterations required, but is able to remove |
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[368] | 206 | // the sidelobes likely to occur near strong lines. |
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| 207 | // Later a better criterion may be implemented, e.g. |
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| 208 | // taking into consideration the brightness of different lines. Now |
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[881] | 209 | // use the simplest solution |
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[368] | 210 | // temp_mask - mask to work with (may be different from original mask as |
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| 211 | // the lines previously found may be masked) |
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| 212 | // lines2update - a list of lines to work with |
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| 213 | // nothing will be done if it is empty |
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| 214 | // max_box_nchan - channels in the running box for baseline filtering |
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| 215 | void keepStrongestOnly(const casa::Vector<casa::Bool> &temp_mask, |
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| 216 | std::list<std::pair<int, int> > &lines2update, |
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| 217 | int max_box_nchan) |
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| 218 | throw (casa::AipsError); |
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[297] | 219 | private: |
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[881] | 220 | casa::CountedConstPtr<Scantable> scan; // the scan to work with |
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[297] | 221 | casa::Vector<casa::Bool> mask; // associated mask |
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| 222 | std::pair<int,int> edge; // start and stop+1 channels |
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| 223 | // to work with |
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[881] | 224 | casa::Float threshold; // detection threshold - the |
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[297] | 225 | // minimal signal to noise ratio |
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| 226 | casa::Double box_size; // size of the box for running |
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| 227 | // mean calculations, specified as |
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| 228 | // a fraction of the whole spectrum |
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| 229 | int min_nchan; // A minimum number of consequtive |
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| 230 | // channels, which should satisfy |
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| 231 | // the detection criterion, to be |
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| 232 | // a detection |
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[369] | 233 | casa::Int avg_limit; // perform the averaging of no |
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| 234 | // more than in_avg_limit |
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| 235 | // adjacent channels to search |
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| 236 | // for broad lines. see setOptions |
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[370] | 237 | casa::uInt last_row_used; // the Row number specified |
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| 238 | // during the last findLines call |
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[297] | 239 | std::list<std::pair<int, int> > lines; // container of start and stop+1 |
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| 240 | // channels of the spectral lines |
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| 241 | // a buffer for the spectrum |
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| 242 | mutable casa::Vector<casa::Float> spectrum; |
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[352] | 243 | }; |
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[297] | 244 | |
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[352] | 245 | // |
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| 246 | /////////////////////////////////////////////////////////////////////////////// |
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| 247 | |
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[297] | 248 | } // namespace asap |
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[881] | 249 | #endif // #ifndef STLINEFINDER_H |
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