Using efficiency curve in outer applications

When an efficiency curve is constructed in HyperLab's detector efficiency analysis module, the fitted orthogonal polynomial is available from the File / Generic info menu item or in efficiency reports. An example polynomial may be the following:

Eff = exp(-11069.2*0.000654323*T[0]

-542.452 *0.00261785*T[1] -83.9643 *0.00614508*T[2]

+ 56.176 *0.0107488*T[3] -38.0378 *0.0227131*T[4]

+ 4.23398*0.0361133*T[5] + 2.91758*0.109829*T[6]

)

X = -2.92876 +0.485424*log(E_keV)

T[0] = 1.0

T[1] = X -0.279333

T[2] = (X +0.276447 )*T[1] -0.0624734*T[0]

T[3] = (X -0.193059 )*T[2] -0.181482 *T[1]

T[4] = (X -0.0543797)*T[3] -0.326837 *T[2]

T[5] = (X +0.0860381)*T[4] -0.223959 *T[3]

T[6] = (X -0.0991865)*T[5] -0.395568 *T[4]

A corresponding c++ calculation function is the following:

double D4_Eff(double E_keV) {

double T[7], X = -2.92876 +0.485424*log(E_keV);

T[0] = 1.0;

T[1] = X -0.279333;

T[2] = (X +0.276447 )*T[1] -0.0624734*T[0];

T[3] = (X -0.193059 )*T[2] -0.181482 *T[1];

T[4] = (X -0.0543797)*T[3] -0.326837 *T[2];

T[5] = (X +0.0860381)*T[4] -0.223959 *T[3];

T[6] = (X -0.0991865)*T[5] -0.395568 *T[4];

double Eff = exp( -11069.2*0.000654323*T[0] -542.452*0.00261785*T[1] -83.9643*0.00614508*T[2] +56.176*0.0107488*T[3] -38.0378*0.0227131*T[4] +4.23398*0.0361133*T[5] +2.91758*0.109829*T[6]);

return Eff;

}

This formula above may be transformed into an identical regular polynomial, which describe the logarithmic of efficiency versus the logarithmic of energy:

double D4_LogEff_regular(double LogE) {

double LogEff =

71.50855044771767

-117.10105124644454*LogE

+ 62.00533726638615*pow(LogE,2)

- 15.922301170232352*pow(LogE,3)

+ 2.161709922884965*pow(LogE,4)

- 0.1499226396426317*pow(LogE,5)

+ 0.00419244399979918*pow(LogE,6);

return LogEff;

}