Symmetric and asymmetric discretization

Figure 4: Different discretization schemes for 10 bins per decade. The last two lines are almost indistinguishable.
  
\includegraphics[width=9cm]{emc_long}

The discretization of the tables usually works as

$\displaystyle i_{\textrm{e}}=\textrm{round}(log_{10}(E)*\textrm{icnde})+1$

which is just the inverse of the above formula. In this case, the energy $ E_{i}$ is the middle of a bin going from

$\displaystyle E_{i}/c\le E<E_{i}\times c,   c=10^{1/\textrm{icnde}}$

Each bin will have a contribution of $ w=\frac{E}{E_{i}}$ to ensure energy conservation in the discretization method.

For some applications an asymmetric binning method can be advantageous.In this case

$\displaystyle i_{\textrm{e}}=\textrm{round}(log_{10}(E)*\textrm{icnde}+\textrm{asbin})+1$

and

$\displaystyle E_{i}\times a/c\le E<E_{i}\times a\times c,    a=10^{\textrm{-asbin}/\textrm{icnde}}$

i.e. the borders of the bin are shifted by a factor $ a$ or by $ \textrm{-asbin/icnde }$ on a $ \log_{10}$-scale. Which value is suitable has to be found empirically by comparing MC and CE. E.g. for electromagnetic CE, a value of $ \textrm{asbin$=-0.07$ }$proved useful for when $ \textrm{icnde=10}$, see Fig. 4. But better is

Hans-Joachim Drescher 2006/10/17