Re: [ccp4bb] Anomalous signal to noise details

d solvent > content screening, etc. ;-) Feel free to ask for more. > > Best regards, > > Petr > > > > PS: Although tested on a number of cases, the command line is more stable > than the GUI. > > > > *From:* CCP4 bulletin board *On Behalf Of *David > Wat

Re: [ccp4bb] Anomalous signal to noise details

command line is more stable than the GUI. From: CCP4 bulletin board On Behalf Of David Waterman Sent: Friday, December 18, 2020 12:53 PM To: CCP4BB@JISCMAIL.AC.UK Subject: [ccp4bb] Anomalous signal to noise details Hi folks The paper "Substructure solution with SHELXD<https://journals.iu

Re: [ccp4bb] Anomalous signal to noise details

Conventionally (e.g. in cryo-EM) the SNR is taken as a ratio of averages, either the ratio of the variance of the signal (average of signal squared) to the variance of the noise, i.e. var(signal) / var(noise), or the square root of that, i.e. sd(signal) / sd(noise). See here: https://en.wikipedia.

Re: [ccp4bb] Anomalous signal to noise details

@JISCMAIL.AC.UK Subject: [ccp4bb] Anomalous signal to noise details Hi folks The paper "Substructure solution with SHELXD<https://journals.iucr.org/d/issues/2002/10/02/gr2280/index.html>" (Schneider & Sheldrick, 2002) describes how data can be truncated at the resolution

Re: [ccp4bb] Anomalous signal to noise details

> I don't know the justification; maybe just experience? Surely the higher the > better. I've seen George Sheldrick deriving the value of ~0.8 when there is > _no_ anom signal but I forgot the details, sorry ... It is derived from the mean absolute error (cf. p414 in Chapter 8 of BMC, with hel

Re: [ccp4bb] Anomalous signal to noise details

Hi David, On Fri, 18 Dec 2020 11:53:08 +, David Waterman wrote: >Hi folks > >The paper "Substructure solution with SHELXD >" >(Schneider & Sheldrick, 2002) describes how > >data can be truncated at the resolution at which [ΔF t

Re: [ccp4bb] Anomalous signal to noise details

Dear David, On Fri, Dec 18, 2020 at 11:53:08AM +, David Waterman wrote: > The paper "Substructure solution with SHELXD > " > (Schneider & Sheldrick, 2002) describes how > > data can be truncated at the resolution at which [ΔF to

[ccp4bb] Anomalous signal to noise details

Hi folks The paper "Substructure solution with SHELXD " (Schneider & Sheldrick, 2002) describes how data can be truncated at the resolution at which [ΔF to its estimated > standard deviation as a function of the resolution] drops to