[ccp4bb] AW: [ccp4bb] AW: [ccp4bb] AW: [EXTERNAL] Re: [ccp4bb] number of frames to get a full dataset?

2020-07-03 Thread Schreuder, Herman /DE
Hi David, you are right, the M in MPR is just a count of “whatever” is averaged to get the final intensities. However, from this “inexhaustible thread” it is also clear that there will be no agreement on what to call this “whatever”  Best, Herman Von: David Waterman Gesendet: Freitag, 3.

Re: [ccp4bb] AW: [ccp4bb] AW: [ccp4bb] AW: [EXTERNAL] Re: [ccp4bb] number of frames to get a full dataset?

2020-07-03 Thread Gerard Bricogne
Dear Herman and David, This thread seems inexhaustible :-) . On the matter of "measurement" vs. "observation", we seem again to be in a situation described by the British idiom "half of one and half-a-dozen" of the other, i.e. distinct but synonymous terms between which a choice is

Re: [ccp4bb] AW: [ccp4bb] AW: [ccp4bb] AW: [EXTERNAL] Re: [ccp4bb] number of frames to get a full dataset?

2020-07-03 Thread John R Helliwell
Dear Colleagues, Now that Herman has announced a quietude I thought you might enjoy this quite short report on a synchrotron radiation issue that came up some years back via the JSR Main Editors into the IUCr Nomenclature Committee, chaired by Andre Authier, Past President of the IUCr:-

Re: [ccp4bb] AW: [ccp4bb] AW: [EXTERNAL] Re: [ccp4bb] number of frames to get a full dataset?

2020-07-03 Thread David Waterman
Hi Herman, I started googling and ended up completely lost down a rabbit hole (have a look here if you want to see what I mean: https://plato.stanford.edu/entries/measurement-science/). As a result I'm no longer sure I know what the word "measurement" means! I tried to simplify things with a

[ccp4bb] AW: [ccp4bb] AW: [ccp4bb] AW: [EXTERNAL] Re: [ccp4bb] number of frames to get a full dataset?

2020-07-03 Thread Schreuder, Herman /DE
Dear David, Thank you for your reaction. It has become clear to me that although most people understand what I intended with “measurement”, in practice it is very much in the eye of the beholder. It was suggested in the BB to use observation instead, but I am fairly sure that some people will

Re: [ccp4bb] [EXTERNAL] Re: [ccp4bb] number of frames to get a full dataset?

2020-07-03 Thread Navdeep Sidhu
Dear Ian, I stand corrected: I should have realized before writing rather than afterwards that you were surely stressing the formalization (or formalisation) part. Cheers, Navdeep --- On 02.07.20 22:09, Ian Tickle wrote: > > Hi Navdeep > > Yes good point, the principle of redundancy (though

Re: [ccp4bb] AW: [ccp4bb] AW: [EXTERNAL] Re: [ccp4bb] number of frames to get a full dataset?

2020-07-03 Thread David Waterman
Hi Herman, I like the idea of MPR, but I continue to worry about the term "measurement". The intensity associated with a particular reflection is a fit based on a scaling model, and ultimately, depending on your integration software, may be linked to a weighted sum of two raw measurements: the

Re: [ccp4bb] [EXTERNAL] Re: [ccp4bb] number of frames to get a full dataset?

2020-07-03 Thread Winter, Graeme (DLSLtd,RAL,LSCI)
Thanks Ian - I think you raise some excellent points - while I think the general reader (TM) would understand that redundancy and multiplicity mean broadly the same thing in Table 1, I think having program developers document _precisely_ what they mean by those values would be very valuable. I

[ccp4bb] AW: [ccp4bb] AW: [EXTERNAL] Re: [ccp4bb] number of frames to get a full dataset?

2020-07-03 Thread Schreuder, Herman /DE
Dear Ian, Since some very advanced countries still use miles, Fahrenheit and inches, I did not expect anything to change. It was an escalating discussion in this thread on data completeness(!) on the use of multiplicity vs redundancy that made me suggest a different term. Except for an

Re: [ccp4bb] AW: [EXTERNAL] Re: [ccp4bb] number of frames to get a full dataset?

2020-07-02 Thread Ian Tickle
Well I very much doubt that many software developers are going to trawl through all their code, comments, output statements & documentation to change 'redundancy' or 'multiplicity' to 'MPR' or whatever terminology is agreed on (assuming of course we do manage to come to an agreement, which I

Re: [ccp4bb] [EXTERNAL] Re: [ccp4bb] number of frames to get a full dataset?

2020-07-02 Thread Ian Tickle
Hi Navdeep Yes good point, the principle of redundancy (though they wouldn't have used that term!) has a very long history, but von Neumann did more than anyone before him to formalise it:

Re: [ccp4bb] number of frames to get a full dataset?

2020-07-02 Thread Bernhard Rupp
There is probably some justification for the absence of 'reflection' (as used in crystallography) - in 'purist' Physics. The process itself is not a 'reflection', despite that it can be macroscopically described (in first approximation at least, and good enough for finding diffraction spot

Re: [ccp4bb] [EXTERNAL] Re: [ccp4bb] number of frames to get a full dataset?

2020-07-02 Thread Navdeep Sidhu
Dear Ian, You seem to be slightly off there: The successful use of repeating observations to reduce (especially systematic) observational error predates von Neumann by at least 4 centuries. One of the first instances of its use was in the 1500s, due to a migrant scientist working in Denmark and

Re: [ccp4bb] AW: [EXTERNAL] Re: [ccp4bb] number of frames to get a full dataset?

2020-07-02 Thread Harry Powell - CCP4BB
Dear all I’ve been persuaded that MPR is a useful name (and see that there are shortcomings with both “multiplicity” and “redundancy") and I agree with much of what’s been said most recently in this thread. BTW, just because the Physics definition of a measurement/quantity/whatever is given

[ccp4bb] AW: [EXTERNAL] Re: [ccp4bb] number of frames to get a full dataset?

2020-07-02 Thread Schreuder, Herman /DE
Dear all, While following the development of this thread, I am truly amazed how people cling to names for the number of measurements per reflection whose meaning: * Depends on the cultural/engineering/scientific context * Can only be understood by experts * Where the experts, as

Re: [ccp4bb] number of frames to get a full dataset?

2020-07-02 Thread David Waterman
It is hard for us to rise above these cultural differences, so perhaps the adoption of a third, precisely-defined, and neutral term is indeed warranted. MPR seems a good start, but it forces us to think about what we mean by measurement. My feeling is that a diffraction spot can be measured in

Re: [ccp4bb] [EXTERNAL] Re: [ccp4bb] number of frames to get a full dataset?

2020-07-02 Thread John R Helliwell
Good morning Jose, The devil is always on the detail:- You are of course correct that I had presumed, as Ethan pointed out, a sub 10 fsec pulse. Neutrons creating magnetic waves, you are again correct, “spin echo“ does occur, but without damage though as neutrons have such gentle energies

Re: [ccp4bb] [EXTERNAL] Re: [ccp4bb] number of frames to get a full dataset?

2020-07-01 Thread Ethan A Merritt
On Wednesday, 1 July 2020 18:50:57 PDT Jose Brandao-Neto wrote: > Hi Ian, good to hear! Hi everyone, thanks for the etymological - and > etiological - discussion. I'm good whatever the choice. > > John, I beg to differ with the absolute statement that xfels offer damage > free hkls - back in

Re: [ccp4bb] [EXTERNAL] Re: [ccp4bb] number of frames to get a full dataset?

2020-07-01 Thread Jose Brandao-Neto
Hi Ian, good to hear! Hi everyone, thanks for the etymological - and etiological - discussion. I'm good whatever the choice. John, I beg to differ with the absolute statement that xfels offer damage free hkls - back in 2016 yet another great experimental work, by Inoue et al

Re: [ccp4bb] number of frames to get a full dataset?

2020-07-01 Thread jp d
since i am not getting shit/shite done may i also point out aluminium/aluminum On Wednesday, July 1, 2020, 11:52:21 AM PDT, James Holton wrote: Sorry to take this thread on a detour/diversion: What I was attempting to point out below, perhaps unclearly, is that the different

Re: [ccp4bb] number of frames to get a full dataset?

2020-07-01 Thread James Holton
Sorry to take this thread on a detour/diversion: What I was attempting to point out below, perhaps unclearly, is that the different interpretations of the word "redundant" are a cultural difference.  As a student of multiple English languages perhaps I can explain: Few US English speakers

Re: [ccp4bb] [EXTERNAL] Re: [ccp4bb] number of frames to get a full dataset?

2020-07-01 Thread John R Helliwell
Dear Ian, I take issue with your assertion below that “the totally precise **scientific** meaningis an **engineering**” definition. Science and engineering are not the same. Health and safety leads to the need in engineering for redundancy and indeed safety factors. In essence, in

Re: [ccp4bb] [EXTERNAL] Re: [ccp4bb] number of frames to get a full dataset?

2020-07-01 Thread Goldman, Adrian
I find, when discussing definitions of words, it’s always good to look in the OED (well, the SOED, I don’t have the big one). For redundant (redundancy being defined as the state or quality of being redundant), we find: 1. Superabundant, superfluous, excessive. b. Characterised by superfluity

[ccp4bb] AW: [ccp4bb] [EXTERNAL] Re: [ccp4bb] number of frames to get a full dataset?

2020-07-01 Thread Hughes, Jonathan
hi ian, oh no! all those trump fans across the pond will love the "hypothesis of evolution" idea. they won't know the word "hypothesis" of course, but unfortunately you might get famous for it anyhow. cheers jon Von: CCP4 bulletin board Im Auftrag von Ian Tickle Gesendet: Mittwoch, 1. Juli

Re: [ccp4bb] [EXTERNAL] Re: [ccp4bb] number of frames to get a full dataset?

2020-07-01 Thread Ian Tickle
Yes this seems to be a common misunderstanding, that the meanings of words such as 'redundancy' have to be the same in an informal non-scientific context and in a formal technical/scientific context. So we can say that in an informal context, 'redundancy' means "unnecessary duplication (or

Re: [ccp4bb] AW: [ccp4bb] [EXTERNAL] Re: [ccp4bb] number of frames to get a full dataset?

2020-07-01 Thread Dirk Kostrewa
Dear Kay & Gerard, the only reason, why I want to count differently, is to distinguish between true and pseudo-multiplicity. Apparently, I get on thin ice by trying to define "identical" reflections ... maybe, instead, we should start working with unmerged data in all programs. If I remember

Re: [ccp4bb] AW: [ccp4bb] [EXTERNAL] Re: [ccp4bb] number of frames to get a full dataset?

2020-07-01 Thread Kay Diederichs
Dear Dirk, one cannot fully correct radiation damage. Normal scaling procedures take care of the average decay by a smooth resolution-dependant function. Zero-dose extrapolation goes beyond that but needs all symmetry mates - this does not fulfill your definition of "identical". If we really

Re: [ccp4bb] AW: [ccp4bb] [EXTERNAL] Re: [ccp4bb] number of frames to get a full dataset?

2020-07-01 Thread Dirk Kostrewa
Dear Gerard and Kay, yes, you are both right - I have totally forgotten radiation damage! And correcting for this really makes a difference! However, if radiation damage is corrected for reflections measured at different time points under the same geometry, does anything speak against it,

Re: [ccp4bb] AW: [ccp4bb] [EXTERNAL] Re: [ccp4bb] number of frames to get a full dataset?

2020-07-01 Thread Kay Diederichs
Dear Dirk, XDS_ASCII.HKL (and equivalent files from other processing software) gives you all the information that you're after, since every reflection is stored individually. However when you analyze that, you will find that in a data set that comprises less than 360 degrees of rotation, there

Re: [ccp4bb] AW: [ccp4bb] [EXTERNAL] Re: [ccp4bb] number of frames to get a full dataset?

2020-07-01 Thread Gerard Bricogne
Dear Dirk, Aren't you for getting about radiation damage? The n measurements of the same hkl with the same geometry would not be equivalent, although they would enable the tracking of radiation damage without the confounding with absorption effects that comes from considering

Re: [ccp4bb] AW: [ccp4bb] [EXTERNAL] Re: [ccp4bb] number of frames to get a full dataset?

2020-07-01 Thread Dirk Kostrewa
Dear Herman, I think, your MPR proposal is a great idea and would like to second it! And I would also like to propose that data processing programs just average "identical" reflections measured under the same geometry and count them only once (*), so that, in the end, we will get a realistic

Re: [ccp4bb] [EXTERNAL] Re: [ccp4bb] number of frames to get a full dataset?

2020-07-01 Thread John R Helliwell
Good morning Jon, Ah yes that is a good word from quantum mechanics but no it isn’t in the IUCr Dictionary, nor in the Statistical Descriptors section on Recommendations. http://ww1.iucr.org/iucr-top/comm/cnom/statdes/recomm.html In Laue mode, Xray or neutron, the MPR should be large enough to

[ccp4bb] AW: [ccp4bb] AW: [ccp4bb] [EXTERNAL] Re: [ccp4bb] number of frames to get a full dataset?

2020-07-01 Thread Schreuder, Herman /DE
Dear Frank, in general it is not possible to determine the intensity of a reflection from a single fine slice. One needs slices for the complete reflection. Also, like Bernard, you are imposing criteria on the MPR, which are not imposed on the multiplicity/redundancy/abundancy. All I ask the

[ccp4bb] AW: [ccp4bb] [EXTERNAL] Re: [ccp4bb] number of frames to get a full dataset?

2020-07-01 Thread Schreuder, Herman /DE
Dear Bernard and other bulletin board members, As Gerard mentioned, current data processing programs and table 1’s do not make this distinction, but of course, you are free to ask the community to introduce it. My proposal to use “measurements per reflections” is not a joke. It exactly

Re: [ccp4bb] number of frames to get a full dataset?

2020-06-30 Thread 00000c2488af9525-dmarc-request
I think it is quite an interesting question in principle for Laue crystallography (now probably only relevant in the neutron world?) since, for example, if one had a crystal in the 432 point group, you could collect an essentially complete dataset with one 'image'. Given that each image can take

Re: [ccp4bb] number of frames to get a full dataset?

2020-06-30 Thread Gerard Bricogne
Dear Ed, Concerning your remark that "use of terms redundancy and multiplicity to describe the same concept is by itself redundant", one could perhaps say that redundancy is an abstract property of a dataset, while multiplicity is a numerical attribute. Redundancy is desirable because if

Re: [ccp4bb] [EXTERNAL] Re: [ccp4bb] number of frames to get a full dataset?

2020-06-30 Thread 00000c2488af9525-dmarc-request
Hello JohnDoes the IUCr dictionary list 'degeneracy'?Jon CooperOn 30 Jun 2020 17:11, Gerard Bricogne wrote:Dear Bernhard, That is true, and the discrepancies between repeated measurements of the same hkl would have to be parametrised differently from those between symmetry-related ones

Re: [ccp4bb] [EXTERNAL] Re: [ccp4bb] number of frames to get a full dataset?

2020-06-30 Thread Gerard Bricogne
Dear Bernhard, That is true, and the discrepancies between repeated measurements of the same hkl would have to be parametrised differently from those between symmetry-related ones (e.g. in terms of radiation damage only, while the others would also involve absorption effects). However I am

Re: [ccp4bb] [EXTERNAL] Re: [ccp4bb] number of frames to get a full dataset?

2020-06-30 Thread Frank von Delft
Gerard, fantastic proposal - let's call it "abundancy"!!! Which developer will be the first to change their logfile? On 30/06/2020 16:38, Gerard Bricogne wrote: Dear Phil, I would like to make an attempt to not let this question get mired in exchanges of well-researched linguistic

Re: [ccp4bb] [EXTERNAL] Re: [ccp4bb] number of frames to get a full dataset?

2020-06-30 Thread Bernhard Rupp
.…but there is a difference whether I measure the same identical hkl over again or ‘preferably in more than one symmetry-equivalent position’, to quote the IUCr. So do we have a MPSR for the same reflection and a MPRR for the related reflections? Cacophonically yours, BR From: CCP4

Re: [ccp4bb] [EXTERNAL] Re: [ccp4bb] number of frames to get a full dataset?

2020-06-30 Thread Gerard Bricogne
Dear Phil, I would like to make an attempt to not let this question get mired in exchanges of well-researched linguistic arguments at risk of being drowned in a cacophony of sound bites :-) . You refer to the days of SCALA, at which time data were collected on CCD detectors, whose

Re: [ccp4bb] [EXTERNAL] Re: [ccp4bb] number of frames to get a full dataset?

2020-06-30 Thread John R Helliwell
Dear Herman, I think that MPR is a very neat and tidy, excellent, proposal. Moreover it uses the word “measurements”, and we are an experimental based science. I support it. Great. Greetings, John Emeritus Professor John R Helliwell DSc > On 30 Jun 2020, at 15:10, Schreuder, Herman /DE >

Re: [ccp4bb] number of frames to get a full dataset?

2020-06-30 Thread Edwin Pozharski
Replicate is a good option with its own problems as it can be seen as referring to exact copy which multiple measurements clearly aren't. It does have an advantage of being the word used by non-crystallographers though. As a lame attempt at joke, use of terms redundancy and multiplicity to

[ccp4bb] AW: [EXTERNAL] Re: [ccp4bb] number of frames to get a full dataset?

2020-06-30 Thread Schreuder, Herman /DE
Dear BB, Since there does not seem a generally accepted term for the subject of this discussions, and since even the IUCR scriptures do not give any guidance, I would propose to introduce a completely new term: Measurements per reflection or MPR This term is politically neutral, should

Re: [ccp4bb] [EXTERNAL] Re: [ccp4bb] number of frames to get a full dataset?

2020-06-30 Thread Phil Evans
I changed the annotation from “Redundancy” to “Multiplicity” in Scala, later in Aimless, after I was taken to task by Elspeth Garman with the argument as stated, that if it’s redundant why did you bother to measure it? (this one could run and run …) Phil > On 30 Jun 2020, at 14:07, Ian Tickle

Re: [ccp4bb] [EXTERNAL] Re: [ccp4bb] number of frames to get a full dataset?

2020-06-30 Thread Ian Tickle
I agree about RAID but I would go a lot further. There seems to be some confusion here over the correct meaning of 'redundant' as used in a scientific context. I don't think looking it up in an English dictionary is very helpful. So as has been mentioned the non-scientific and rather imprecise

Re: [ccp4bb] [EXTERNAL] Re: [ccp4bb] number of frames to get a full dataset?

2020-06-30 Thread David Schuller
By all means, if you still have "disks" you should get rid of them, and replace them with some modern storage. On 2020-06-29 21:17, Edward A. Berry wrote: Now can we get rid of all the superfluous disks in our RAID? Or at least not replace them when they fail? On 06/29/2020 06:24 PM,

Re: [ccp4bb] number of frames to get a full dataset?

2020-06-30 Thread John R Helliwell
Dear Colleagues, In an effort to break this naming deadlock, and with Massimo and Ian not showing up as yet, I checked the IUCr Dictionary. “Redundancy“ and “Multiplicity“ are not listed. The more generic term “Statistical Descriptors“ is though and even offers Recommendations:-

Re: [ccp4bb] number of frames to get a full dataset?

2020-06-30 Thread Phil Jeffrey
The people that already use multiplicity are going to find reasons why it's the superior naming scheme - although the underlying reason has a lot to do with negative associations with 'redundant', perhaps hightened in the current environment. And conversely redundant works for many others -

Re: [ccp4bb] number of frames to get a full dataset?

2020-06-30 Thread Winter, Graeme (DLSLtd,RAL,LSCI)
Or, we could accept the fact that crystallographers are kinda used to multiplicity of an individual Miller index being different to multiplicity of observations, and in Table 1 know which one you mean?  Given that they add new information (at the very least to the scaling model) they are

Re: [ccp4bb] [EXTERNAL] Re: [ccp4bb] number of frames to get a full dataset?

2020-06-30 Thread David Waterman
Ok, the analogy is not great because most reflection data sets have some "fault tolerance" whereas RAID 0 does not. But the point is that anything that is not an exact copy and brings actual information should not be considered "redundant" On Tue, 30 Jun 2020, 09:00 David Waterman, wrote: >

Re: [ccp4bb] [EXTERNAL] Re: [ccp4bb] number of frames to get a full dataset?

2020-06-30 Thread David Waterman
Reflections are as "redundant" as the disks in a RAID 0 array On Tue, 30 Jun 2020, 02:49 James Holton, wrote: > What could possibly go wrong? > > -James Holton > MAD Scientist > > On 6/29/2020 6:17 PM, Edward A. Berry wrote: > > Now can we get rid of all the superfluous disks in our RAID? Or at

Re: [ccp4bb] [EXTERNAL] Re: [ccp4bb] number of frames to get a full dataset?

2020-06-29 Thread James Holton
What could possibly go wrong? -James Holton MAD Scientist On 6/29/2020 6:17 PM, Edward A. Berry wrote: Now can we get rid of all the superfluous disks in our RAID? Or at least not replace them when they fail? On 06/29/2020 06:24 PM, Andreas Förster wrote: I like to think that the reflections

Re: [ccp4bb] [EXTERNAL] Re: [ccp4bb] number of frames to get a full dataset?

2020-06-29 Thread Edward A. Berry
Now can we get rid of all the superfluous disks in our RAID? Or at least not replace them when they fail? On 06/29/2020 06:24 PM, Andreas Förster wrote: I like to think that the reflections I carefully measured at high multiplicity are not redundant, which the dictionary on my computer

Re: [ccp4bb] number of frames to get a full dataset?

2020-06-29 Thread Bernhard Rupp
Ah…the rise of the replicants … https://www.youtube.com/watch?v=yWPyRSURYFQ …and don’t forget the and the Voight-Kampff Test results in Table 1. Best, BR From: Pierre Rizkallah Sent: Monday, June 29, 2020 15:46 To: b...@hofkristallamt.org; CCP4BB@JISCMAIL.AC.UK Subject: RE:

Re: [ccp4bb] number of frames to get a full dataset?

2020-06-29 Thread Pierre Rizkallah
You’re missing out on a grand opportunity for iconoclasm here. Try out ‘Degree of Replication’ or ‘Average Replication’ or ‘Replicate Frequency’. Any other offerings! P. *** Dr Pierre Rizkallah, Senior Lecturer Structural Biology Institute of

Re: [ccp4bb] number of frames to get a full dataset?

2020-06-29 Thread Bernhard Rupp
I think it is time to escalate that discussion to crystallographic definition purists like Massimo or to a logical consistency proponent like Ian who abhors definitional vacuum  Cheers, BR From: CCP4 bulletin board On Behalf Of Andreas Förster Sent: Monday, June 29, 2020 15:24 To:

Re: [ccp4bb] number of frames to get a full dataset?

2020-06-29 Thread Andreas Förster
I like to think that the reflections I carefully measured at high multiplicity are not redundant, which the dictionary on my computer defines as "not or no longer needed or useful; superfluous" and the American Heritage Dictionary as "exceeding what is necessary or natural; superfluous" and

Re: [ccp4bb] number of frames to get a full dataset?

2020-06-29 Thread James Holton
I have found that the use of "redundancy" vs "multiplicity" correlates very well with the speaker's favorite processing software.  The Denzo/HKL program scalepack outputs "redundancy", whereas scala/aimless and other more Europe-centric programs output "multiplicity". At least it is not as

Re: [ccp4bb] number of frames to get a full dataset?

2020-06-25 Thread 00000c2488af9525-dmarc-request
Phil Jefferey was right about the point group (432), which looks like it represents about 0.7 % of the PDB! I tested the completeness with MOSFLM strategy for various sporadic missetting angles and 11 degrees of data does give you around 90 % completeness or more with redundancy close to 2,

Re: [ccp4bb] number of frames to get a full dataset?

2020-06-24 Thread Bernhard Rupp
> Oh, and some of us prefer the word 'multiplicity' ;-0 Hmmm…maybe not. ‘Multiplicity’ in crystallography is context sensitive, and not uniquely defined. It can refer to a. the position multiplicity (number of equivalent sites per unit cell, aka Wyckoff-Multiplicity), the only (!) cif

Re: [ccp4bb] number of frames to get a full dataset?

2020-06-24 Thread Jose Brandao-Neto
To improve both multiplicity, anomalous signal and dose-proofing from a single crystal - complementing the thread and papers suggested so far and thinking of a strategy that covers low symmetry - the excellent approach introduced at the SLS (Basu et al,

Re: [ccp4bb] number of frames to get a full dataset?

2020-06-23 Thread Peat, Tom (Manufacturing, Parkville)
I have no disagreement that anomalous is helpful and very useful data to have. So I’m in agreement with you and Bernhard without any reservations whatsoever. It just so happens that 360 degrees of data in the P1 spacegroup does not give you very good anomalous signal. In my limited experience,

Re: [ccp4bb] number of frames to get a full dataset?

2020-06-23 Thread 00000c2488af9525-dmarc-request
Well, it can still help. I used to be a great fan of inverse-beam expts! Oh, and some of us prefer the word 'multiplicity' ;-0Jon CooperOn 23 Jun 2020 22:04, "Peat, Tom (Manufacturing, Parkville)" wrote: I would just like to point out that for those of us who have worked too many times with P1

Re: [ccp4bb] number of frames to get a full dataset?

2020-06-23 Thread Bernhard Rupp
Tom makes a good point. The minimum RS coverage necessary to obtain a unique data set is just a simple calculation that involves no experimental reality. To judge the expected usefulness of the data, you need to have some idea about the possible errors, random and systematic. Random is

Re: [ccp4bb] number of frames to get a full dataset?

2020-06-23 Thread Peat, Tom (Manufacturing, Parkville)
I would just like to point out that for those of us who have worked too many times with P1 or P21 that even 360 degrees will not give you 'super' anomalous differences. I'm not a minimalist when it comes to data- redundancy is a good thing to have. cheers, tom Tom Peat Proteins Group Biomedical

Re: [ccp4bb] number of frames to get a full dataset?

2020-06-23 Thread Bernhard Rupp
1/48th of reciprocal space is the minimum in certain SGs.. Table 6.6 in BMC or http://www.ruppweb.org/new_comp/spacegroup_decoder.htm Best, BR From: CCP4 bulletin board On Behalf Of 0c2488af9525-dmarc-requ...@jiscmail.ac.uk Sent: Tuesday, June 23, 2020 08:11 To:

Re: [ccp4bb] number of frames to get a full dataset?

2020-06-23 Thread 00000c2488af9525-dmarc-request
Someone told me there is a cubic space group where you can get away with something like 11 degrees of data. It would be interesting if that's correct. These minimum ranges for data collection rely on the crystal being pre-oriented, which is unheard-of these days, although they can help if someone

Re: [ccp4bb] number of frames to get a full dataset?

2020-06-23 Thread Andreas Förster
Hi Murpholino, in my opinion (*), the question is neither number of frames nor degrees. The only thing that matters to your crystal is dose. How many photons does your crystal take before it dies? Consequently, the question to ask is How best to use photons. Some people have done exactly that.

Re: [ccp4bb] number of frames to get a full dataset?

2020-06-22 Thread David Schuller
The old saying was degrees, not frames. If your frame width is not 1 degree, the result will differ accordingly. One factor is whether the detector is centered or offset, and whether it is large enough to get the entire pattern. If the detector is offset, you are not getting the full

Re: [ccp4bb] number of frames to get a full dataset?

2020-06-22 Thread Diana Tomchick
There are lots of places where you could find this information (many textbooks, articles, etc.) but one that I use for classes is quite good due to ease of understanding. It’s part of the Proceedings of the CCP4 Study Weekend on Data Collection and Processing. There are other quite excellent

Re: [ccp4bb] number of frames to get a full dataset?

2020-06-22 Thread Srivastava, Dhiraj
Well, its not no. of frames but minimum degree of crystal rotation. A goggle search gave me this article. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5557013/ Dhiraj From: CCP4 bulletin board on behalf of Murpholino Peligro Sent: Monday, June 22, 2020 5:03