Dear @horvathd ,

That’s OK. By the way, I have another question is that the same variable in different user routines.

The variable `WVLNGT`

used in `wvlnsh.f`

(it is output variable and the value is negative, negative just represent energy or wavelength), should I use `abs(WVLNGT)`

When performing arithmetic operations in `abscff.f`

(as a input variable)?

Does any other parameters(energy, momentum, wavelength, angular and so on) have a positive or negative distinction in code?

Dear XIONG BANGPING,

The input variable `WVLNGT`

always corresponds to the absorbed photon wavelength and is always positive.

On the other hand, the values of `WVSHPH`

correspond to either the energy (if positive) or the wavelenght (if negative).

For the routine `wvlnsh.f`

, only the variable `WVSHPH`

has a negative/positive distinction. If you mean in general in the FLUKA code, this is a too general question to answer here.

Read the relevant page in the manual for details on the ` wvlnsh.f`

routine: 13.2.32. wvlnsh.f — FLUKA Manual