clipper_util.h

//C Copyright (C) 2000-2006 Kevin Cowtan and University of York
//L
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//L  and conditions of version 2.1 of the GNU Lesser General Public
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//L     not covered by this licence.)'
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#ifndef CLIPPER_UTIL
#define CLIPPER_UTIL


#include "clipper_precision.h"


namespace clipper
{


  class Util
  {
  private:
    typedef union { uitype32 i; ftype32 f; } U32;
    typedef union { uitype64 i; ftype64 f; } U64;
  public:
    Util();   

    static const ftype& nan() { return nan_; }
    static const float& nanf() { return nanf_; }
    static const double& nand() { return nand_; }
    inline static void set_null( ftype32& f ) { U32* const u1=(U32* const)&f; const U32* const u2=(const U32* const)&nanf_; u1->i = u2->i; }
    inline static void set_null( ftype64& f ) { U64* const u1=(U64* const)&f; const U64* const u2=(const U64* const)&nand_; u1->i = u2->i; }
    inline static bool is_null( const ftype32& f ) { U32 u1,u2; u1.f = f; u2.f = nanf_; return ( u1.i == u2.i ); }
    inline static bool is_null( const ftype64& f ) { U64 u1,u2; u1.f = f; u2.f = nand_; return ( u1.i == u2.i ); }

    inline static bool is_nan( const ftype32 f ) { U32 u; u.f = f; return ((u.i&CLIPPER_NAN_MASK_A_32)==CLIPPER_NAN_MASK_A_32); }

    inline static bool is_nan( const ftype64 f ) { U64 u; u.f = f; return ((u.i&CLIPPER_NAN_MASK_A_64)==CLIPPER_NAN_MASK_A_64); }

    inline static bool isnan(const ftype32 f) { U32 u; u.f = f; return ((u.i&CLIPPER_NAN_MASK_A_32)==CLIPPER_NAN_MASK_A_32)&&((u.i&CLIPPER_NAN_MASK_B_32)!=0U); }

    inline static bool isnan(const ftype64 f) { U64 u; u.f = f; return ((u.i&CLIPPER_NAN_MASK_A_64)==CLIPPER_NAN_MASK_A_64)&&((u.i&CLIPPER_NAN_MASK_B_64)!=0U); }
    static ftype sim( const ftype& x );
    static ftype invsim( const ftype& x );
    static ftype sim_integ( const ftype& x );
    static ftype sim_deriv( const ftype& x );
    static ftype sim_deriv_recur( const ftype& x );
    static ftype atanh( const ftype& x ) { return log((1.0+x)/(1.0-x))/2.0; }
    static ftype bessel_i0( const ftype& x );
    static ftype u2b( const ftype& x ) { return x * eightpi2_; }
    static ftype b2u( const ftype& x ) { return x / eightpi2_; }
    template<class T> inline static T mean( const T& pl, const T& mi )
      {
        if ( Util::is_nan(pl) ) return mi;
        else if (Util::is_nan(mi) ) return pl;
        else return 0.5*(pl+mi);
      }
    template<class T> inline static T sig_mean( const T& pl, const T& mi, const T& cov )
      {
        if ( Util::is_nan(pl) ) return mi;
        else if (Util::is_nan(mi) ) return pl;
        else if (Util::is_nan(cov) ) return 0.5*sqrt(pl*pl+mi*mi);
        else return 0.5*sqrt(pl*pl+mi*mi+2*cov);
      }

    inline static int intf( const ftype& a ) { return int( floor( a ) ); }
    inline static int intc( const ftype& a ) { return int( ceil( a ) ); }
    inline static int intr( const ftype& a ) { return int( rint( a ) ); }

    inline static ftype mod( const ftype& a, const ftype& b )
      { ftype c = fmod(a, b); if (c < 0) c+=b; return c;}
    inline static int mod( const int& a, const int& b )
      { int c = a%b; if (c < 0) c+=b; return c; }
    template<class T> inline static T max(const T& a, const T& b)
      { return (a > b) ? a : b; }
    template<class T> inline static T min(const T& a, const T& b)
      { return (a < b) ? a : b; }
    template<class T> inline static T bound( const T& min, const T& val, const T& max ) { return ( (val < max) ? ( (val > min ) ? val : min ) : max ); }
    template<class T> inline static void swap( T& a, T& b )
      { T c = a; a = b; b = c; }
    template<class T> inline static void swap( T& a, T& b, T& c )
      { c = a; a = b; b = c; }
    template<class T> inline static T sqr( const T& a ) { return a*a; }
    template<class T> inline static T isqrt( const T& n )
      { return T(floor(sqrt(ftype(n)))); }

    inline static const ftype& pi() { return onepi_; }
    inline static const ftype& twopi() { return twopi_; }
    inline static const ftype& twopi2() { return twopi2_; }
    inline static const ftype& eightpi2() { return eightpi2_; }
    static ftype d2rad( const ftype& x );
    static ftype rad2d( const ftype& x );

  private:
    static float  nanf_;  
    static double nand_;  
    static ftype  nan_;   
    static ftype onepi_;  
    static ftype twopi_;  
    static ftype twopi2_; 
    static ftype eightpi2_; 
    static ftype d2rad_;  
    static ftype sim_a;   
    static ftype sim_b;   
    static ftype sim_c;   
    static ftype sim_d;   
    static ftype sim_e;   
    static ftype sim_A;   
    static ftype sim_B;   
    static ftype sim_C;   
    static ftype sim_g;   
    static ftype sim_p;   
    static ftype sim_q;   
    static ftype sim_r;   
  };

} // namespace clipper

#endif