Re: [ccp4bb] Any simple way to scale 2 MTZ?

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CCP4bb <-- 1999 <-- November 1999 <-- 30 November 1999

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Subject: Re: Any simple way to scale 2 MTZ?
From: Francois Berenger berenger {- at -} RIKEN {- dot -} JP
Date: 2010-03-12

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From: junfeng liu jliu {- at -} NIMR {- dot -} MRC {- dot -} AC {- dot -} UK
Date: 2010-03-12

Subject: Re: Any simple way to scale 2 MTZ?
From: Graeme Winter graeme {- dot -} winter {- at -} GOOGLEMAIL {- dot -} COM
Date: 2010-03-12

Hi Francois,

As I understand this, they (the F's) should be already on an
"absolute" scale as determined by the Wilson stats as TRUNCATE does
this scaling. What SCALEIT does is to scale the data sets together in
terms of an overall (or anisotropic) temperature factor and overall
scale, so that the differences between related observations can be
interpreted more sensibly.

I am sure by now that the authors of these programs will be online and
able to provide a more authoritative answer.

I guess what would be helpful here is to know what you are trying to
achieve in this scaling.

Best wishes,

Graeme

On 12 March 2010 09:27, Francois Berenger wrote:
> Graeme Winter wrote:
>>
>> Hi Francois,
>>
>> SCALEIT in CCP4 sounds like the tool you want - this is for scaling
>> e.g. native and derivitive data sets together. You will need to cad
>> together the two files first though.
>
> My crystallographer colleague tells me that if we use
> scaleit there is a risk if there are multiple copies in the ASU.
>
> So, we should scale both data sets to absolute scale.
>
>> This is illustrated in the tutorials here:
>>
>>
>> http://www.ccp4.ac.uk/dist/examples/tutorial/html/heavy-tutorial-mad.html#step_4a
>>
>> Best wishes,
>>
>> Graeme
>>
>> On 12 March 2010 08:17, Francois Berenger wrote:
>>>
>>> Hello,
>>>
>>> Is there a magic tool doing the job of scaling 2 MTZ to the same scale?
>>>
>>> For the moment I know with ccp4:
>>> rwcontents then wilson then mtzutils
>>>
>>> with phenix:
>>> lsq_scale (in fact I am lying, I was forced to run ccp4's cad before)
>>>
>>> Is there a simpler way with ccp4?
>>> As I am not a crystallographer, I am afraid I can do many
>>> different stupid errors when I have to use many tools for just
>>> one task.
>>>
>>> Regards,
>>> Francois.
>>>
>
>

CCP4bb navigation

CCP4bb <-- 1999 <-- November 1999 <-- 30 November 1999

Previous message:
Subject: Re: Any simple way to scale 2 MTZ?
From: Francois Berenger berenger {- at -} RIKEN {- dot -} JP
Date: 2010-03-12

Next message:
Subject: Re: protein crystallization problem
From: junfeng liu jliu {- at -} NIMR {- dot -} MRC {- dot -} AC {- dot -} UK
Date: 2010-03-12