Re: [ccp4bb] Scale factor in ccp4

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CCP4bb <-- 2007 <-- March 2007 <-- 22 March 2007

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Subject: Workshop: Macromolecular Crystallography at PETRA III
From: Michele Cianci michele {- dot -} cianci {- at -} EMBL-HAMBURG {- dot -} DE
Date: 2007-03-22

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From: Ranvir Singh rsvatsa {- at -} YAHOO {- dot -} COM
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Subject: Re: Scale factor in ccp4
From: Eleanor Dodson ccp4 {- at -} YSBL {- dot -} YORK {- dot -} AC {- dot -} UK
Date: 2007-03-22

Yes -
and actually Johan's suggestion is the best - one should not merge two
sets of already merged data,
better is to scale and merge all together in scalepack..
Eleanor

George M. Sheldrick wrote:
> A less convoluted method is to read both .sca files into xprep, scale
> them together and write out the combined .sca file.
>
> George
>
> Prof. George M. Sheldrick FRS
> Dept. Structural Chemistry,
> University of Goettingen,
> Tammannstr. 4,
> D37077 Goettingen, Germany
> Tel. +49-551-39-3021 or -3068
> Fax. +49-551-39-2582
>
>
> On Thu, 22 Mar 2007, Eleanor Dodson wrote:
>
>
>> When youu run scalepack2mtz the GUI always follows this by TRUNCATE to convert
>> Is to Fs
>>
>> At that stage there is an attempt to put the data on roughly an absolute
>> scale, either using the NRES you gave as input or if that is not set, I think
>> assuming 50% of the cell volume is protein.
>> Anyway the scales WILL be different after TRUNCATE.
>>
>> If you want to scale them together more carefully you will need to run cad,
>> then SCALEIT ( on the GUI undr exptl phases)
>> THEN convert each I1 and I2 back to a sca file ..
>>
>> Seems a lot of trouble! Why do you need this?
>>
>> Eleanor
>>
>> yang li wrote:
>>
>>> Hi:
>>> I have two set of data from the same crystal with the names 1.sca and
>>> 2.sca,
>>> they have different Intensity values due to different scale factors.
>>> Now I use Scalepack2mtz
>>> convert them to 1.mtz and 2.mtz, then use cad to merge to a cad.mtz, then
>>> convert it to cad.sca file, I find that the Intensity values in this
>>> cad.sca arediffrent from
>>> 1.sca and 2.sca, I wonder if the program has scaled the values itself?
>>> If that is true,
>>> which program did this, Scalepack2mtz or cad?
>>> Thanks!
>>>
>>> Li Yang
>>>
>>>
>>>
>
>
>

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CCP4bb <-- 2007 <-- March 2007 <-- 22 March 2007

Previous message:
Subject: Workshop: Macromolecular Crystallography at PETRA III
From: Michele Cianci michele {- dot -} cianci {- at -} EMBL-HAMBURG {- dot -} DE
Date: 2007-03-22

Next message:
Subject: Re: Highest shell standards
From: Ranvir Singh rsvatsa {- at -} YAHOO {- dot -} COM
Date: 2007-03-22