Revert updates in iSAM2

[Riccardo Giubilato]

Hi, first of all thank you all for this awesome library. I am working on real time SLAM using iSAM2 as the optimization backend in a keyframe-based scenario. Sometimes it may happen that an iSAM2 update diverges from the actual solution, that is of course physiological when solving non-linear problems. Since, after evaluating the final error using ISAM::error(), I can spot divergent optimizations I would know if I could revert the last update leaving the values of the nodes involved as they were previously. Secondly, from the current interface to iSAM2, is it possible to split the processes of enlarging the factor graph with new observations and performing an update? Thank you! Riccardo

[Frank Dellaert]

Don't think you can undo. And also no on the split, I think.

[Frank Dellaert]

Support question, not an actual issue