Line data    Source code

       1             : //# SpectralIndex.cc:
       2             : //# Copyright (C) 1998,1999,2000,2003
       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 addressed 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             : //# $Id: SpectralIndex.cc 21292 2012-11-28 14:58:19Z gervandiepen $
      27             : 
      28             : #include <components/ComponentModels/PowerLogPoly.h>
      29             : #include <casacore/casa/Arrays/Vector.h>
      30             : #include <casacore/casa/Arrays/ArrayLogical.h>
      31             : #include <casacore/casa/Containers/RecordInterface.h>
      32             : #include <casacore/casa/Exceptions/Error.h>
      33             : #include <casacore/casa/Arrays/IPosition.h>
      34             : #include <casacore/casa/Logging/LogIO.h>
      35             : #include <casacore/casa/Logging/LogOrigin.h>
      36             : #include <casacore/casa/BasicMath/Math.h>
      37             : #include <casacore/measures/Measures/MFrequency.h>
      38             : #include <casacore/measures/Measures/MCFrequency.h>
      39             : #include <casacore/measures/Measures/MeasConvert.h>
      40             : #include <casacore/casa/Quanta/MVFrequency.h>
      41             : #include <casacore/casa/Quanta/Quantum.h>
      42             : #include <casacore/casa/Utilities/Assert.h>
      43             : #include <casacore/casa/Utilities/DataType.h>
      44             : #include <casacore/casa/BasicSL/String.h>
      45             : 
      46             : using namespace casacore;
      47             : namespace casa { //# NAMESPACE CASA - BEGIN
      48             : 
      49           0 : PowerLogPoly::PowerLogPoly() : SpectralModel() {}
      50             : 
      51           0 : PowerLogPoly::PowerLogPoly(
      52             :   const MFrequency& refFreq, const Vector<Double> coeffs
      53           0 : ) : SpectralModel(refFreq), _coeffs(coeffs.copy()),
      54           0 : _errors(Vector<Double>(coeffs.size(), 0)) {}
      55             : 
      56           0 : PowerLogPoly::PowerLogPoly(const PowerLogPoly& other) 
      57           0 :   : SpectralModel(other), _coeffs(other._coeffs.copy()),
      58           0 :   _errors(other._errors.copy()) {}
      59             : 
      60           0 : PowerLogPoly::~PowerLogPoly() {}
      61             : 
      62           0 : PowerLogPoly& PowerLogPoly::operator=(const PowerLogPoly& other) {
      63           0 :   if (this != &other) {
      64           0 :     SpectralModel::operator=(other);
      65           0 :     _coeffs.resize(other._coeffs.size());
      66           0 :     _coeffs = other._coeffs.copy();
      67           0 :     _errors.resize(other._errors.size());
      68           0 :     _errors = other._errors.copy();
      69             :   }
      70           0 :   return *this;
      71             : }
      72             : 
      73           0 : ComponentType::SpectralShape PowerLogPoly::type() const {
      74           0 :   return ComponentType::PLP;
      75             : }
      76             : 
      77           0 : Double PowerLogPoly::_getNu0(const MFrequency::Ref& refFrame) const {
      78           0 :   const MFrequency& refFreq(refFrequency());
      79           0 :   const auto nu0 = refFrame == refFreq.getRef()
      80           0 :     ? refFreq.getValue().getValue()
      81           0 :     : MFrequency::Convert(refFreq, refFrame)().getValue().getValue();
      82           0 :   ThrowIf(nu0 <= 0.0, "the reference frequency is zero or negative");
      83           0 :   return nu0;
      84             : }
      85             : 
      86           0 : Double PowerLogPoly::_getIntensityRatio(Double x) const {
      87           0 :   const auto logx = log(x);
      88           0 :   Double exponent = 0;
      89           0 :   for(uInt i=0; i<_coeffs.size(); ++i) {
      90           0 :     if (i == 0) {
      91           0 :       exponent = _coeffs[i];
      92             :     }
      93           0 :     else if (i == 1) {
      94           0 :       exponent += _coeffs[i] * logx;
      95             :     }
      96           0 :     else if (i == 2) {
      97           0 :       exponent += _coeffs[i] * logx * logx;
      98             :     }
      99             :     else {
     100           0 :       exponent += _coeffs[i] * pow(logx, i);
     101             :     }
     102             :   }
     103           0 :   return pow(x, exponent);
     104             : }
     105             : 
     106           0 : Double PowerLogPoly::sample(const MFrequency& centerFreq) const {
     107           0 :     const auto x = centerFreq.getValue()/_getNu0(centerFreq.getRef());
     108           0 :     return _getIntensityRatio(x);
     109             : }
     110             : 
     111           0 : void PowerLogPoly::sampleStokes(
     112             :     const MFrequency& centerFreq, Vector<Double>& iquv
     113             : ) const {
     114           0 :     ThrowIf(iquv.size() != 4, "Four stokes parameters in iquv are expected");
     115           0 :     iquv[0] *= sample(centerFreq);
     116             :     // TODO add full stokes support.
     117           0 : }
     118             : 
     119           0 : void PowerLogPoly::sample(
     120             :     Vector<Double>& scale,  const Vector<MFrequency::MVType>& frequencies, 
     121             :     const MFrequency::Ref& refFrame
     122             : ) const {
     123           0 :     const auto nSamples = frequencies.size();
     124           0 :     ThrowIf(
     125             :         scale.size() != nSamples, 
     126             :         "A Vector of length " + String::toString(nSamples) + " is required"
     127             :     );
     128           0 :     const auto nu0 = _getNu0(refFrame);
     129           0 :     for (uInt i=0; i<nSamples; ++i) {
     130           0 :         scale[i] = _getIntensityRatio(frequencies[i].getValue()/nu0);
     131             :     }
     132           0 : }
     133             : 
     134           0 : void PowerLogPoly::sampleStokes(
     135             :     Matrix<Double>& iquv, const Vector<MFrequency::MVType>& frequencies, 
     136             :         const MFrequency::Ref& refFrame
     137             : ) const {
     138           0 :     ThrowIf(
     139             :         iquv.shape() != IPosition(2, frequencies.size(), 4),
     140             :         "Incorrect Matrix shape"
     141             :     );
     142           0 :     const auto nSamples = frequencies.size();
     143           0 :     const auto nu0 = _getNu0(refFrame);
     144           0 :     for (uInt i=0; i<nSamples; ++i) {
     145           0 :         iquv(i, 0) *= _getIntensityRatio(frequencies[i].getValue()/nu0);
     146             :     }
     147             :     // TODO full polarization implementation to come
     148           0 : }
     149             :   
     150           0 : SpectralModel* PowerLogPoly::clone() const {
     151           0 :   SpectralModel* tmpPtr = new PowerLogPoly(*this);
     152           0 :   AlwaysAssert(tmpPtr, AipsError);
     153           0 :   return tmpPtr;
     154             : }
     155             : 
     156           0 : uInt PowerLogPoly::nParameters() const {
     157           0 :   return _coeffs.size();
     158             : }
     159             : 
     160           0 : void PowerLogPoly::setParameters(const Vector<Double>& newSpectralParms) {
     161           0 :     _coeffs.resize(0);
     162           0 :     _coeffs = newSpectralParms.copy();
     163           0 :     const auto s = _coeffs.size();
     164           0 :     if (_errors.size() != s) {
     165           0 :         _errors.resize(s, True);
     166             :     }
     167           0 : }
     168             : 
     169           0 : Vector<Double> PowerLogPoly::parameters() const {
     170           0 :   return _coeffs.copy();
     171             : }
     172             : 
     173           0 : void PowerLogPoly::setErrors(const Vector<Double>& newSpectralErrs) {
     174           0 :     ThrowIf(anyLT(newSpectralErrs, 0.0), "The errors must be non-negative.");
     175           0 :     _errors.resize(newSpectralErrs.size());
     176           0 :     _errors = newSpectralErrs.copy();
     177           0 :     const auto s = _errors.size();
     178           0 :     if (_coeffs.size() != s) {
     179           0 :         _coeffs.resize(s, True);
     180             :     }
     181           0 : }
     182             : 
     183           0 : Vector<Double> PowerLogPoly::errors() const {
     184           0 :   return _errors.copy();
     185             : }
     186             : 
     187           0 : Bool PowerLogPoly::fromRecord(
     188             :   String& errorMessage,  const RecordInterface& record) {
     189           0 :   if (! SpectralModel::fromRecord(errorMessage, record)) {
     190           0 :     return false;
     191             :   }
     192           0 :   if (!record.isDefined(String("coeffs"))) {
     193           0 :     errorMessage += "The record must have an 'coeffs' field";
     194           0 :     return false;
     195             :   }
     196             :   {
     197           0 :      const RecordFieldId coeffs("coeffs");
     198           0 :      Vector<Double> coeffVal;
     199           0 :      switch (record.dataType(coeffs)) {
     200           0 :      case TpArrayDouble:
     201             :      case TpArrayFloat:
     202             :      case TpArrayInt:
     203           0 :        coeffVal = record.asArrayDouble(coeffs);
     204           0 :        break;
     205           0 :      default:
     206           0 :        errorMessage += "The 'coeff' field must be an array of numbers";
     207           0 :        return false;
     208             :      }
     209           0 :      setParameters(coeffVal);
     210           0 :   }
     211             :   // TODO full stokes implementation to come
     212             :   {
     213           0 :       Vector<Double> errorVals(nParameters(), 0.0);
     214           0 :       if (record.isDefined("error")) {
     215           0 :         const RecordFieldId error("error");
     216           0 :         switch (record.dataType(error)) {
     217           0 :         case TpArrayDouble:
     218             :         case TpArrayFloat:
     219             :         case TpArrayInt: {
     220           0 :           const auto x = record.asArrayDouble(error);
     221           0 :           if (x.size() != nParameters()) {
     222           0 :             errorMessage = "Coefficient and error array lengths are not equal";
     223           0 :             return false;
     224             :           }
     225             :           else {
     226           0 :             setErrors(x);
     227             :           }
     228           0 :         }
     229           0 :         break;
     230           0 :         default:
     231           0 :           errorMessage += "The 'error' field must be an array of numbers";
     232           0 :           return false;
     233             :         }
     234           0 :      }
     235           0 :   }
     236           0 :   return true;
     237             : }
     238             : 
     239           0 : Bool PowerLogPoly::toRecord(
     240             :   String& errorMessage, RecordInterface& record) const {
     241           0 :   if (! SpectralModel::toRecord(errorMessage, record)) {
     242           0 :     return false;
     243             :   }
     244           0 :   record.define("coeffs", parameters());
     245             :   // TODO full stokes support still to come
     246           0 :   record.define("error", errors());
     247           0 :   return true;
     248             : }
     249             : 
     250           0 : Bool PowerLogPoly::convertUnit(
     251             :   String&, const RecordInterface& 
     252             : ) {
     253             :   // parameters are dimensionless, no conversion can be done
     254           0 :   return true;
     255             : }
     256             : 
     257           0 : Bool PowerLogPoly::ok() const {
     258           0 :   if (! SpectralModel::ok()) {
     259           0 :     return false;
     260             :   }
     261           0 :   if (refFrequency().getValue().getValue() <= 0.0) {
     262           0 :     LogIO logErr(LogOrigin("PowerLogPoly", "ok()"));
     263             :     logErr << LogIO::SEVERE << "The reference frequency is zero or negative!" 
     264           0 :            << LogIO::POST;
     265           0 :     return false;
     266           0 :   }
     267           0 :   if (anyGT(abs(_coeffs), 100.0)) {
     268           0 :     LogIO logErr(LogOrigin("PowerLogPoly", "ok()"));
     269             :     logErr << LogIO::SEVERE << "At least one coefficient is greater than 100!" 
     270           0 :            << LogIO::POST;
     271           0 :     return false;
     272           0 :   }
     273           0 :   return true;
     274             : }
     275             : 
     276             : } //# NAMESPACE CASA - END