Hi,
On Thu, Nov 10, 2011 at 4:32 PM, David Lonie <lonieda...@gmail.com> wrote:
> Hi list,
>
> In atom.h, there are the following three functions:
>
> //! \return the internal atom index (e.g., inside an OBMol)
> unsigned int GetIdx() const { return((int)_idx); }
> unsigned int GetIndex() const { return _idx - 1; }
> unsigned long GetId() const { return _id; }
>
> Can someone explain and/or document these in a bit more detail? I was
> quite surprised that GetIdx and GetIndex are defined differently. What
> is the role of _idx vs _id? Is there a reason that in GetIdx _idx is
> cast from uint->int, then (implicitly) back to a uint?
>
> I also see:
>
> unsigned int _idx; //!< unique node index (GetIdx(), SetIdx())
> unsigned long _id; //!< unique id
>
> I'm not sure what the difference between these descriptions is either?
The idx is an atom index that goes from 1 to N (N = number of atoms).
This is the _idx field and can be retreived using GetIdx().
The index (GetIndex()) is also an atom index but starts from 0 (0 to
N-1). This is the _idx - 1 field. This function was added for more
conformance to the bond indexes which start from 0.
The _id (GetId()) field is a unique id that does not change if atoms
are deleted and can be to identify atoms during an OBMol's lifespan.
> The reason I ask is that I'm trying to limit an OBFF calculation with
> OBForceField::AddInt[er,ra]Group[s], which takes the atom index, but
> it's not clear to me whether this means the index, the idx, or the id.
You usually have to see at the specific code.
> Thanks in advance,
>
> Dave
>
> ------------------------------------------------------------------------------
> RSA(R) Conference 2012
> Save $700 by Nov 18
> Register now
> http://p.sf.net/sfu/rsa-sfdev2dev1
> _______________________________________________
> OpenBabel-Devel mailing list
> OpenBabel-Devel@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/openbabel-devel
>
------------------------------------------------------------------------------
RSA(R) Conference 2012
Save $700 by Nov 18
Register now
http://p.sf.net/sfu/rsa-sfdev2dev1
_______________________________________________
OpenBabel-Devel mailing list
OpenBabel-Devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/openbabel-devel
