Re: [ccp4bb] Protein Crystallography challenges Standard Model precision

-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Hi James, I would say that 0.333 (in a scientific context) implies that I am confident about this number up to the third decimal point, i.e. 0.3325 = x = 0.3334. This gives you an idea of the precision. 1/3 is not a scientific format, but a

Re: [ccp4bb] Protein Crystallography challenges Standard Model precision

bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] On Behalf Of Zbyszek Otwinowski Sent: Dienstag, 22. Juli 2014 23:49 To: CCP4BB@JISCMAIL.AC.UK Subject: Re: [ccp4bb] Protein Crystallography challenges Standard Model precision The least-square procedure for unit cell parameter refinement provides very

Re: [ccp4bb] Protein Crystallography challenges Standard Model precision

Where is it written that compactness of representation and accuracy/precision are the same thing? Is 1/3 more or less precise than 0.333 ? If mmCIF were a binary floating-point format file, there would be more decimal places in the precision of the stored value for the unit cell, despite

Re: [ccp4bb] Protein Crystallography challenges Standard Model precision

: [ccp4bb] Protein Crystallography challenges Standard Model precision Where is it written that compactness of representation and accuracy/precision are the same thing?  Is 1/3 more or less precise than 0.333 ? If mmCIF were a binary floating-point format file, there would be more decimal places

Re: [ccp4bb] Protein Crystallography challenges Standard Model precision

Subject: Re: [ccp4bb] Protein Crystallography challenges Standard Model precision Where is it written that compactness of representation and accuracy/precision are the same thing? Is 1/3 more or less precise than 0.333 ? If mmCIF were a binary floating-point format file, there would be more decimal

Re: [ccp4bb] Protein Crystallography challenges Standard Model precision

-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Hi Bernhard, A look at the methods section might give you a clue. Neither XDS nor XSCALE create mmCIF - files (you are talking about mmCIF, not CIF - subtle, but annoying difference), so that the choice is limited. I guess some programmer (rather

Re: [ccp4bb] Protein Crystallography challenges Standard Model precision

I took a look at both the PDB and CIF headers for the coordinates for 4C69 and they have normal looking numbers with three digits following the decimal point. According to the coordinate file header this entry was processed by PDBE. It would be interesting to hear from the PDBE staff if the

Re: [ccp4bb] Protein Crystallography challenges Standard Model precision

Error estimates for the unit cell dimensions in macromolecular crystallography belong to atypical category of uncertainty estimates. Random error contribution in most cases is below 0.001A, so it can be neglected. Wavelength calibration error can be also made very small; however, I do not know

Re: [ccp4bb] Protein Crystallography challenges Standard Model precision

Dear Zbyszek, when you optimise a set of parameters against a set of data, I guess you can also provide their errors. If I understand correctly, this comes with least-squares-routines. I only pointed out that cell errors are listed in the XDS output (provided you refine them, of course). I am

Re: [ccp4bb] Protein Crystallography challenges Standard Model precision

The least-square procedure for unit cell parameter refinement provides very precise estimates of uncertainty. Why they are so precise? Because we use many thousands of unmerged reflections to determine the precision 1 to 6 parameters (unit cell parameters). However, although error propagation

Re: [ccp4bb] Protein Crystallography challenges Standard Model precision

Shouldn't the cell dimensions be identical in the coordinate file and in the structure factor file? In this case they are not. Frances = Bernstein + Sons * * Information Systems Consultants