JMatrix2S.cc

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#include <string>
#include <iostream>
#include <iomanip>

#include "TRandom3.h"

#include "JLang/JException.hh"
#include "JMath/JMatrix2S.hh"

#include "Jeep/JParser.hh"
#include "Jeep/JMessage.hh"


/**
 * \file
 *
 * Example program to test inversion of symmetric matrix.
 * \author mdejong
 */
int main(int argc, char**argv)
{
  using namespace std;

  double precision;
  int    debug;

  try {

    JParser<> zap("Example program to test inversion of symmetric matrix.");

    zap['e'] = make_field(precision)      = 1.0e-6;
    zap['d'] = make_field(debug)          = 3;

    zap(argc, argv);
  }
  catch(const exception &error) {
    FATAL(error.what() << endl);
  }

  using namespace JPP;


  gRandom->SetSeed(0);

  const Double_t xmin = -1.0;
  const Double_t xmax = +1.0;
 

  JMatrix2D A(gRandom->Uniform(xmin,xmax), 0.0,                       
              gRandom->Uniform(xmin,xmax), gRandom->Uniform(xmin,xmax));
    
  A.a01 = A.a10;


  DEBUG("Matrix A" << endl);
  DEBUG(A << endl);

  NOTICE("Determinant A " << A.getDeterminant() << endl);

  try {

    JMatrix2S B(A);
    
    B.invert();

    DEBUG("Matrix A^-1" << endl);
    DEBUG(B << endl);

    NOTICE("Determinant A^-1 = " << B.getDeterminant() << endl);

    JMatrix2D C(A * B);

    DEBUG("Matrix A x A^-1" << endl);
    DEBUG(C << endl);

    NOTICE("Determinant (A x A^-1)           = " << C.getDeterminant()                      << endl);
    NOTICE("Determinant A x Determinant A^-1 = " << A.getDeterminant() * B.getDeterminant() << endl);
    NOTICE("A x A^-1 = I ? "                     << C.isIdentity(precision)                 << endl);
      
    if (!C.isIdentity(precision)) {
      ERROR("Matrix A x A^-1 /= I" << endl);
    }      

    JMatrix2D D = C - JMatrix2D::getIdentity();

    DEBUG("Matrix D = C - I" << endl);
    DEBUG(D << endl);

    ASSERT(C.isIdentity(precision));
  }
  catch (const JException& error) {
    FATAL(error << endl);
  }

  return 0;
}