1 | //# Spectral2Estimate.cc: Member templates for SpectralEstimate |
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2 | //# Copyright (C) 2001,2002,2003,2004 |
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3 | //# Associated Universities, Inc. Washington DC, USA. |
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4 | //# |
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5 | //# This library is free software; you can redistribute it and/or modify it |
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6 | //# under the terms of the GNU Library General Public License as published by |
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7 | //# the Free Software Foundation; either version 2 of the License, or (at your |
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8 | //# option) any later version. |
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9 | //# |
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10 | //# This library is distributed in the hope that it will be useful, but WITHOUT |
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11 | //# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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12 | //# FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public |
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13 | //# License for more details. |
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14 | //# |
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15 | //# You should have received a copy of the GNU Library General Public License |
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16 | //# along with this library; if not, write to the Free Software Foundation, |
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17 | //# Inc., 675 Massachusetts Ave, Cambridge, MA 02139, USA. |
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18 | //# |
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19 | //# Correspondence concerning AIPS++ should be addressed as follows: |
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20 | //# casacore::Internet email: aips2-request@nrao.edu. |
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21 | //# Postal address: AIPS++ Project Office |
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22 | //# National Radio Astronomy Observatory |
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23 | //# 520 Edgemont Road |
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24 | //# Charlottesville, VA 22903-2475 USA |
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25 | //# |
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26 | //# $Id: Spectral2Estimate.tcc 21465 2014-06-19 05:56:56Z gervandiepen $ |
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27 | |
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28 | //# Includes |
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29 | #include <components/SpectralComponents/SpectralEstimate.h> |
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30 | |
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31 | #include <casa/BasicMath/Math.h> |
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32 | #include <casa/BasicSL/Constants.h> |
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33 | #include <casa/Utilities/Assert.h> |
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34 | #include <components/SpectralComponents/CompiledSpectralElement.h> |
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35 | #include <components/SpectralComponents/GaussianSpectralElement.h> |
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36 | #include <components/SpectralComponents/PolynomialSpectralElement.h> |
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37 | |
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38 | namespace casa { //#Begin namespace casa |
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39 | |
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40 | //# Member templates |
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41 | template <class MT> |
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42 | const SpectralList &SpectralEstimate::estimate(const casacore::Vector<MT> &prof, |
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43 | casacore::Vector<MT> *der) { |
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44 | if (prof.nelements() != lprof_p) { |
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45 | delete [] deriv_p; deriv_p = 0; lprof_p = 0; |
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46 | lprof_p = prof.nelements(); |
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47 | deriv_p = new casacore::Double[lprof_p]; |
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48 | }; |
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49 | // Check if signal in window |
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50 | if (!window(prof)) return slist_p; |
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51 | // Limit window |
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52 | windowEnd_p = min(windowEnd_p+q_p , casacore::Int(lprof_p)); |
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53 | windowLow_p = max(windowLow_p-q_p , 0 ); |
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54 | // Get the second derivatives |
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55 | findc2(prof); |
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56 | // Next for debugging |
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57 | if (der) { |
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58 | for (casacore::uInt i=0; i<lprof_p; i++) (*der)[i] = deriv_p[i]; |
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59 | }; |
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60 | // Find the estimates (sorted) |
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61 | findga(prof); |
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62 | // cout << slist_p << endl; |
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63 | return slist_p; |
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64 | } |
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65 | |
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66 | template <class MT> |
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67 | const SpectralList& SpectralEstimate::estimate(const casacore::Vector<MT>& x, |
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68 | const casacore::Vector<MT>& y) |
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69 | { |
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70 | if (x.nelements() != y.nelements()) { |
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71 | throw(AipsError("Abcissa and ordinate vectors must be the same length")); |
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72 | } |
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73 | if (x.nelements()==1) { |
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74 | throw(AipsError("Not enough elements in vectors")); |
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75 | } |
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76 | // Get pixel-based estimate (into slist_p) |
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77 | estimate(y); |
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78 | // Convert |
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79 | for (casacore::uInt i=0; i<slist_p.nelements(); i++) { |
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80 | if (slist_p[i]->getType() != SpectralElement::GAUSSIAN) { |
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81 | throw AipsError("Non-gaussian spectral types cannot be estimated"); |
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82 | } |
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83 | const GaussianSpectralElement elIn = *dynamic_cast<const GaussianSpectralElement *>(slist_p[i]); |
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84 | GaussianSpectralElement elOut = convertElement (x, elIn); |
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85 | slist_p.set(elOut, i); |
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86 | } |
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87 | return slist_p; |
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88 | } |
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89 | |
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90 | |
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91 | template <class MT> |
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92 | casacore::uInt SpectralEstimate::window(const casacore::Vector<MT> &prof) { |
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93 | windowLow_p =0; |
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94 | windowEnd_p = 0; |
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95 | if (!useWindow_p || rms_p <= 0.0 || lprof_p == 0) { |
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96 | if (regionEnd_p) { |
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97 | windowLow_p = min(max(0,regionLow_p),casacore::Int(lprof_p)); |
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98 | windowEnd_p = min(regionEnd_p, casacore::Int(lprof_p)); |
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99 | } else windowEnd_p = lprof_p; |
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100 | return windowEnd_p-windowLow_p; |
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101 | }; |
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102 | // Total flux in profile and max position |
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103 | casacore::Double flux(0.0); |
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104 | casacore::Double pmax(prof(0)); |
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105 | casacore::uInt imax(0); |
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106 | for (casacore::Int i=windowLow_p; i<windowEnd_p; i++) { |
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107 | if (prof(i)>pmax) { |
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108 | pmax = prof(i); |
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109 | imax = i; |
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110 | }; |
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111 | flux += prof(i); |
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112 | }; |
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113 | // No data |
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114 | if (pmax < cutoff_p) return 0; |
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115 | // Window boundaries; new/old base and centre; width |
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116 | casacore::Int width(-1); |
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117 | casacore::Int nw(0); |
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118 | casacore::Double bnew(flux), bold; |
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119 | casacore::Double cnew(imax), cold; |
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120 | do { |
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121 | width++; |
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122 | cold = cnew; |
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123 | bold = bnew; |
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124 | windowLow_p = max(0, casacore::Int(cold-width+0.5)); |
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125 | windowEnd_p = min(casacore::Int(lprof_p), casacore::Int(cold+width+1.5)); |
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126 | // flux and first moment in window |
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127 | casacore::Double s(0); |
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128 | casacore::Double c(0); |
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129 | for (casacore::Int i=windowLow_p; i<windowEnd_p; i++) { |
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130 | s += prof(i); |
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131 | c += i*prof(i); |
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132 | }; |
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133 | bnew = flux-s; |
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134 | nw = lprof_p-windowEnd_p+windowLow_p; |
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135 | if (s != 0.0) { |
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136 | cnew = c/s; |
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137 | if (cnew < 0 || cnew >= lprof_p) cnew = cold; |
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138 | }; |
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139 | } while (abs(bnew-bold) > rms_p && nw); |
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140 | return windowEnd_p-windowLow_p; |
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141 | } |
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142 | |
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143 | template <class MT> |
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144 | void SpectralEstimate::findc2(const casacore::Vector<MT> &prof) { |
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145 | for (casacore::Int i=windowLow_p; i<windowEnd_p; i++) { |
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146 | // Moments |
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147 | casacore::Double m0(0.0); |
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148 | casacore::Double m2(0.0); |
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149 | for (casacore::Int j = -q_p; j <= q_p; j++) { |
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150 | casacore::Int k = i+j; |
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151 | if (k >= 0 && k<casacore::Int(lprof_p)) { |
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152 | // add to moments |
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153 | m0 += prof(k); |
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154 | m2 += prof(k)*j*j; |
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155 | }; |
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156 | }; |
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157 | // get the derivative |
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158 | deriv_p[i] = a_p*(m2-b_p*m0); |
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159 | }; |
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160 | } |
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161 | |
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162 | template <class MT> |
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163 | void SpectralEstimate::findga(const casacore::Vector<MT> &prof) { |
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164 | casacore::Int i(windowLow_p-1); |
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165 | // Window on Gaussian |
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166 | casacore::Int iclo(windowLow_p); |
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167 | casacore::Int ichi(windowLow_p); |
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168 | // Peak counter |
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169 | casacore::Int nmax = 0; |
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170 | GaussianSpectralElement tspel; |
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171 | while (++i < windowEnd_p) { |
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172 | if (deriv_p[i] > 0.0) { |
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173 | // At edge? |
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174 | if (i > windowLow_p && i < windowEnd_p-1) { |
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175 | // Peak in 2nd derivative |
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176 | if (deriv_p[i-1] < deriv_p[i] && deriv_p[i+1] < deriv_p[i]) nmax++; |
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177 | // At start |
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178 | } else if (i == windowLow_p && deriv_p[i+1] < deriv_p[i]) nmax++; |
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179 | // At end of window |
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180 | else if (i == windowEnd_p-1 && deriv_p[i-1] < deriv_p[i]) nmax++; |
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181 | }; |
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182 | switch (nmax) { |
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183 | // Search for next peak |
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184 | case 1: |
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185 | break; |
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186 | // Found a Gaussian |
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187 | case 2: { |
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188 | // Some moments |
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189 | casacore::Double m0m(0); |
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190 | casacore::Double m0(0); |
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191 | casacore::Double m1(0); |
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192 | casacore::Double m2(0); |
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193 | ichi = i; |
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194 | // Do Schwarz' calculation |
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195 | casacore::Double b = deriv_p[iclo]; |
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196 | casacore::Double a = (deriv_p[ichi] - b) / (ichi-iclo); |
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197 | for (casacore::Int ic=iclo; ic<=ichi; ic++) { |
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198 | m0m += min(deriv_p[ic], 0.0); |
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199 | casacore::Double wi = deriv_p[ic] - a*(ic-iclo) - b; |
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200 | m0 += wi; |
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201 | m1 += wi*ic; |
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202 | m2 += wi*ic*ic; |
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203 | }; |
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204 | // determinant |
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205 | casacore::Double det = m2*m0 - m1*m1; |
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206 | if (det > 0.0 && fabs(m0m) > FLT_EPSILON) { |
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207 | casacore::Double xm = m1/m0; |
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208 | casacore::Double sg = 1.69*sqrt(det) / fabs(m0); |
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209 | // Width above critical? |
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210 | if (sg > sigmin_p) { |
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211 | casacore::Int is = casacore::Int(1.73*sg+0.5); |
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212 | casacore::Int im = casacore::Int(xm+0.5); |
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213 | casacore::Double yl(0); |
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214 | if ((im-is) >= 0) yl = prof(im-is); |
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215 | casacore::Double yh(0); |
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216 | if ((im + is) <= casacore::Int(lprof_p-1)) yh = prof(im+is); |
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217 | casacore::Double ym = prof(im); |
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218 | // modified by dmehringer 2012apr03 to deal with 0 denominator |
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219 | // 0.0/0.0 produces NaN on Linux but 0 on OSX |
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220 | casacore::Double pg = (ym-0.5*(yh+yl)); |
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221 | if (pg != 0) { |
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222 | casacore::Double denom = (1.0-exp(-0.5*(is*is)/sg/sg)); |
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223 | if (denom == 0) { |
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224 | throw AipsError("Bailing because division by zero is undefined"); |
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225 | } |
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226 | pg /= denom; |
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227 | } |
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228 | // end dmehring mods |
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229 | pg = min(pg, ym); |
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230 | // cout << "pg " << pg << " cutoff " << cutoff_p << endl; |
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231 | // Above critical level? Add to list |
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232 | if (pg > cutoff_p) { |
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233 | // cout << pg << " " << xm << " " << sg << endl; |
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234 | tspel.setAmpl(pg); |
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235 | tspel.setCenter(xm); |
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236 | tspel.setSigma(sg); |
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237 | slist_p.insert(tspel); |
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238 | }; |
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239 | }; |
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240 | }; |
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241 | // Next gaussian |
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242 | iclo = ichi; |
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243 | nmax--; |
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244 | break; |
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245 | } |
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246 | default: |
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247 | iclo = i+1; |
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248 | break; |
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249 | }; |
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250 | }; |
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251 | } |
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252 | |
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253 | template <class MT> |
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254 | GaussianSpectralElement SpectralEstimate::convertElement (const casacore::Vector<MT>& x, |
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255 | const GaussianSpectralElement& el) const |
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256 | { |
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257 | GaussianSpectralElement elOut = el; |
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258 | const casacore::Int& idxMax = x.nelements()-1; |
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259 | |
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260 | // Get current (pars are amp, center, width as the SpectralElement |
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261 | // will always be a Gaussian) |
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262 | |
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263 | casacore::Vector<casacore::Double> par, err; |
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264 | el.get(par); |
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265 | el.getError(err); |
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266 | |
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267 | // Center |
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268 | |
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269 | casacore::Int cenIdx = casacore::Int(par[1]); |
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270 | |
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271 | // Get the x-increment, local to the center, as best we can from |
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272 | // the abcissa vector. The following algorithm assumes the X |
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273 | // vector is monotonic |
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274 | |
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275 | casacore::Double incX; |
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276 | if (cenIdx-1<0) { |
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277 | incX = x[1] - x[0]; |
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278 | } else if (cenIdx+1>idxMax) { |
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279 | incX = x[idxMax] - x[idxMax-1]; |
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280 | } else { |
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281 | incX = 0.5 * (x(cenIdx+1) - x(cenIdx-1)); |
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282 | } |
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283 | // |
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284 | if (cenIdx<0) { |
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285 | par[1] = incX*par[1] + x[0]; // Extrapolate from x[0] |
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286 | } else if (cenIdx>idxMax) { |
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287 | par[1] = incX*(par[1]-idxMax) + x[idxMax]; // Extrapolate from x[idxMax] |
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288 | } else { |
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289 | casacore::Double dIdx = par[1] - cenIdx; |
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290 | par[1] = x[cenIdx] + dIdx*incX; // casacore::Interpolate |
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291 | } |
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292 | err[1] = abs(err[1] * incX); |
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293 | |
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294 | // Width |
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295 | |
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296 | par[2] = abs(par[2] * incX); |
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297 | err[2] = abs(err[2] * incX); |
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298 | |
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299 | elOut.set(par); |
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300 | elOut.setError(err); |
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301 | return elOut; |
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302 | } |
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303 | |
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304 | |
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305 | } //# End namespace casa |
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