On 8/17/11 4:16 AM, Noel O'Boyle wrote: > Hi all, > > Would it break the API to add another value for the enum > OBStereo::Winding? Current values are Clockwise and AntiClockwise: I'd > like to add Unknown. > > The reason is that people seem to distinguish between unspecified > chirality, and unknown chirality. (Let's not talk about racemic > mixtures right now.) A SMILES string only has syntax for unspecified > chirality, e.g. CC(Br)(Cl)I. However, a MOL file can have a squiggly > line indicating unknown chirality and there's no way to store this > internally (correct me if I'm wrong). We have a system for noting > whether the configuration is specified or unspecified (via > Config.specified), but nothing for storing that "it is specified that > it is unknown".
This is an important distinction: The difference between a known mixture, an unspecified center, and and unknown center. So there are actually four cases: 1. known chirality 2. known mixture 3. unspecified chirality 4. unknown chirality If you add the "unknown" property, you still can't distinguish between #2 and #3. But it's a start. The same thing is true of double bonds. Craig ------------------------------------------------------------------------------ Get a FREE DOWNLOAD! and learn more about uberSVN rich system, user administration capabilities and model configuration. Take the hassle out of deploying and managing Subversion and the tools developers use with it. http://p.sf.net/sfu/wandisco-d2d-2 _______________________________________________ OpenBabel-Devel mailing list OpenBabel-Devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/openbabel-devel
