Excellent point and no, these are not missing reflections. SigF is not zero. Also, if I am not mistaken, missing reflections in the MTZ format are recorded as NaN.
Ed. On Thu, 2011-02-10 at 12:17 +0000, Eleanor Dodson wrote: > Are you sure these are real FP=0 or reflections which werent measured > but have been added for completeness of the h k l list. > The check is whether the SigF is also 0.00 - in that case they are > genuinely missing.. > > Eleanor > > On 02/09/2011 11:34 PM, Ed Pozharski wrote: > > I observe under some conditions that ctruncate sets some reflections > > amplitudes to zero. AFAIU, this should not be happening as even > > negative intensities (there are none in this particular dataset) should > > produce FP>0 upon truncation. > > > > 66 out of ~23000 reflections are zeros after ctruncate is applied. > > Nothing obvious comes up upon inspecting the corresponding hkl's, except > > that one and only one is always zero (sg is P21212, so these are not > > systematic absences). One curious thing is that the I/sigma for these > > reflections is close to the average I/sigma in the highest resolution > > range (but it varies and these reflections are in all resolution > > ranges). > > > > A bug? > > > -- Edwin Pozharski, PhD, Assistant Professor University of Maryland, Baltimore ---------------------------------------------- When the Way is forgotten duty and justice appear; Then knowledge and wisdom are born along with hypocrisy. When harmonious relationships dissolve then respect and devotion arise; When a nation falls to chaos then loyalty and patriotism are born. ------------------------------ / Lao Tse /
