Re: [ccp4bb] Review: Linearity and Resolution in X-Ray Crystallography and Electron Microscopy

2024-10-09 Thread Sindelar, Charles
Randy, what a beautiful paper! I love it. I’m also a huge fan of the you guys’ resolve_cryo_em density modification paper, which had a major impact on my group’s ability to interpret several challenging structures. Many moons ago when I was a postdoc with Niko Grigorieff, I got interested in th

Re: [ccp4bb] happy/sad maps

2023-04-30 Thread Sindelar, Charles
A simple way to visualize what is happening is with UCSF ChimeraX. You can use the gaussian filter function to select either the frown or the smile from the “hidden_frown.map”, and then you can visualize the FFT structure factor magnitudes for each one – here are the commands to do it - open hi

Re: [ccp4bb] happy/sad maps

2023-04-28 Thread Sindelar, Charles
Hi James! I’m not sure exactly what cpp4, coot and phenix do for their FFT’s, but I’m assuming they must mask off the ‘corners’ of the 3D FFT data cube transform (where the frequency is greater than the Nyquist) during the forwards transform. If you take your Cheshire map and do the FFT in mat