AtlasMcWeight Namespace Reference

Typedefs
typedef unsigned int	number_type

Functions
double	decode (number_type binnedWeight)
	Convert weight from unsigned to double. More...
number_type	encode (double weight)

Typedef Documentation

number_type

typedef unsigned int AtlasMcWeight::number_type

Definition at line 20 of file AtlasMcWeight.h.

Function Documentation

decode()

double AtlasMcWeight::decode

(

number_type

binnedWeight

)

Convert weight from unsigned to double.

Definition at line 32 of file AtlasMcWeight.cxx.

                                              {
    short d_pref = (short)(binnedWeight/ONEBILLION);
    int   d_rest = (int)(binnedWeight % ONEBILLION);
    short d_exp  = (short)(d_rest/HUNDREDMIL);
    int   d_prec = d_rest % HUNDREDMIL;
 
    switch(d_pref) {
        case NUMP_EXPP:
            break;
        case NUMNOTP_EXPP:
            d_prec = -d_prec;
            break;
        case NUMP_EXPNOTP:
            d_exp  = -d_exp;
            break;
        case NUMNOTP_EXPNOTP:
            d_prec = -d_prec;
            d_exp  = -d_exp;
            break;
    }
    double wt_decode=d_prec*pow(10,d_exp-NPLACES+1);
    //decoding
#ifdef AMC_DEBUG
    std::cout << "d_pref=" << d_pref << std::endl;
    std::cout << " d_exp=" << d_exp << std::endl;
    std::cout << "d_prec=" << d_prec << std::endl;
    printf("decodd=%.8g \n",wt_decode);
#endif
    return wt_decode;
} 

encode()

AtlasMcWeight::number_type AtlasMcWeight::encode

(

double

weight

)

Definition at line 65 of file AtlasMcWeight.cxx.

                                   { 
    int exponent = int(floor(log10(fabs(weight)))+1);
    if ( abs(exponent) > 9 ) { 
        throw GaudiException( "The MC weight abs value is bigger than 1E9,encoding failed","AtlasMcWeight", StatusCode::FAILURE ); 
    }
 
    number_type wt_prec = int(fabs(weight)*pow(10,(NPLACES-1-exponent)));
    number_type wt_exp = abs(exponent);
    int d_sign = ( weight > 0. ? 0 : 1 );
    int e_sign = ( exponent > 0. ? 0 : 1 );
    number_type wt_pref = d_sign+2*e_sign;
 
    char senc[13];
    snprintf(senc,13,"%u%u%u",wt_pref, wt_exp, wt_prec);
    number_type wt_encode=atoll(senc);
 
#ifdef AMC_DEBUG
    std::cout << " AtlasMcWeight::encode weight = " << weight << std::endl;
    printf("encode parts =%d %d %d \n", wt_pref, wt_exp, wt_prec);
    printf("encoded string=%s \n", senc);
    std::cout << " weight=" << weight << std::endl;
    std::cout << " str weight=" << senc << std::endl;
    std::cout << " exp weight=" << atoll(senc) << std::endl;
    std::cout << " encoded weight=" << wt_encode << std::endl;
#endif
    return wt_encode;
}