Some questions about SOURCE.F. Cosines and position how to define?

Dear expert
When define the beam direction and beam starting position,I noticed noticed the example is different from the course PPT.
In the example the direction is as follows:

But in course PPT,the direction is as follows::

Could you tell me the difference between them?.

I have another irrelevant question. In the “ (radioactive) isotope” part and “ Heavy ion:”, some examples are different. It lacks a few lines of code. I want to know what the functions of these lines of code are and whether they can be omitted

Thanks,look forward to the expert’s reply.

Dear @gao_han,
The slides refer to a new version of the source routine format “source_newgen.f”, which has been simplified to make it more user friendly, while your snapshots refer to the old source routine format “source.f”, which is still working but a bit less user friendly.
The new format is based on Fortran90, therefore its variables have longer and more evocative names. Additionally, a lot of lines that do not have to be touched by users have been moved into library subroutines.
I advise you to work with the new “source_newgen.f”, you will find it simpler and more convenient.

Thanks your reply,I have no problem