miscmaths.cc

/*  miscmaths.cc

    Mark Jenkinson & Mark Woolrich & Christian Beckmann & Tim Behrens, FMRIB Image Analysis Group

    Copyright (C) 1999-2000 University of Oxford  */

/*  CCOPYRIGHT  */

// Miscellaneous maths functions

#include "miscmaths.h"
#include "miscprob.h"
#include "stdlib.h"
#include "newmatio.h"

using namespace std;

namespace MISCMATHS {

  // The following lines are ignored by the current SGI compiler
  //  (version egcs-2.91.57)
  // A temporary fix of including the std:: in front of all abs() etc
  //  has been done for now
  using std::abs;
  using std::sqrt;
  using std::exp;
  using std::log;
  //  using std::pow;
  using std::atan2;


  string size(const Matrix& mat)
  {
    string str = num2str(mat.Nrows())+"*"+num2str(mat.Ncols());
        
    return str;
  }



  float Sinc(const float x) {
    if (fabs(x)<1e-9) {
      return 1-x*x*M_PI*M_PI/6.0;
    } else {
      return sin(M_PI*x)/(M_PI*x);
    }
  }

  double Sinc(const double x) {
    if (fabs(x)<1e-9) {
      return 1-x*x*M_PI*M_PI/6.0;
    } else {
      return sin(M_PI*x)/(M_PI*x);
    }
  }


  // General string/IO functions

  bool isnum(const string& str)
  {
    // assumes that initial whitespace has been removed
    if (isdigit(str[0])) return true;
    if ( (str[0]=='-') || (str[0]=='+') || (str[0]=='.') )  return true;
    return false;
  }
    
  string skip_alpha(ifstream& fs) 
  {
    string cline;