Known issue

From Relion
Jump to navigation Jump to search

Release 1.1

Reconstruction sometimes gives strong stripy artifacts

This is a nasty bug in the reconstruction algorithm, which mostly seems to affect reconstructions from many particles, and only the 3D auto-refine option. The effects on the reconstruction can be disastrous: your molecule may disappear completely and you may end up with a stripy pattern instead. Note that if this happens in only one of the two half-reconstructions, it may go by unnoticed (if you don't inspect both half-reconstruction at each iteration) and may just appear as a sudden drop in resolution during the 3D auto-refine optimization. Somehow, this bug is system-dependent and sometimes hard to reproduce.

However, the bug can be circumvented by changing line 658 in src/backprojector.cpp from:

double myfsc = XMIPP_MAX(0., DIRECT_A1D_ELEM(fsc, i));

to:

double myfsc = XMIPP_MAX(0.001, DIRECT_A1D_ELEM(fsc, i));

Then recompile relion using:

make -j 4 && make install

Thanks to Dieter Blaas (Max F. Perutz Laboratories, Vienna) for reporting this bug. It will be fixed in the next release.