lsmooth: lorentzian smoothing

Lorentzian smoothing with a variable width, which varies as the par2 power of the energy. The width at 6 keV is set with par1.

$$\begin{array}{ll} dC(E) = & \frac{\Sigma(E)}{2\pi[(E-X)^2+(\... ...}A(X)d(X)\\ [.2cm] \Sigma(E) = & \sigma(E/6)^\alpha \end{array}$$

where:

par1=$\sigma$	lorentzian sigma at 6 keV
par2=$\alpha$	power of energy for sigma variation