Re: [ccp4bb] Map density level

2010-09-16 Thread Hailiang Zhang
Thanks! > According to the really good documentation of O, e.g. at > http://xray.bmc.uu.se/alwyn/A-Z_of_O/A-Z_frameset.html > you have to use the command "fm_mode" to change this (and while doing so > might > read Alwyns "FM_Overview" in the same documentation which I just did and > found > very in

Re: [ccp4bb] Map density level

2010-09-16 Thread Dale Tronrud
The main advantage of contouring in absolute units is consistency. The density for a water molecule with a B factor of 20 A^2 will look about the same even if the "noise" level of one map is higher than another. (Within limits, of course) This means that the actual value you contour at isn't a

Re: [ccp4bb] Map density level

2010-09-16 Thread Tim Gruene
According to the really good documentation of O, e.g. at http://xray.bmc.uu.se/alwyn/A-Z_of_O/A-Z_frameset.html you have to use the command "fm_mode" to change this (and while doing so might read Alwyns "FM_Overview" in the same documentation which I just did and found very interesting!). Cheers,

Re: [ccp4bb] Map density level

2010-09-16 Thread Nathaniel Clark
Hi, It can, just do fm-mode select rmsd I am curious though, I have heard that it is 'better' to build in units of absolute density, but I couldn't find any values. Does any one have a suggestion as to what absolute electron density setting is 'correct' for an Fo-Fc difference map? Or do you jus

[ccp4bb] Map density level

2010-09-16 Thread Hailiang Zhang
Hi, I generated a map using FFT, and tried to display it in O. By comparing with coot, I found that the "level" in O seems to be the absolute electron density instead of the sigma level. I am sorry I ask a question more related to O: can O draw the map by a given sigma level instead of the absolut