Thanks! Can you refer me some documents about your following statements:
derivation of sigmaa-weighted 2mFo-DFc formula is by calculating Fourier
coefficients of the following map:
Rescaled composite omit map, where minimal structural element (of the size
about the resolution element) is being omitted and the starting point is
the map with coefficients m*Fo*exp(i*phiCalc)
It seems the above was not involved in Read's publications about SIGMAA.
Thanks again!
Hailiang
> sigmaa-weighted 2mFo-DFc is the _COMPOSIT_OMIT_ map. There is no point in
> calculating omit map of an omit map!!!!
>
> A brief explanation: derivation of sigmaa-weighted 2mFo-DFc formula is by
> calculating Fourier coefficients of the following map:
>
> Rescaled composite omit map, where minimal structural element (of the size
> about the resolution element) is being omitted and the starting point is
> the map with coefficients m*Fo*exp(i*phiCalc)
>
> BTW, composite omit map of a map with coefficients Fo*exp(i*phiCalc) is
> simply Fo-1/2Fc map that after factor of 2 scaling becomes 2Fo-Fc map
>
>> Hi,
>> I want to calculate the sigmaa-weighted 2mFo-DFc composite omit map, and
> tried the following 2 scripts:
>>
>> (1)
>> ./omit hklin ${f}.mtz mapout ${f}.map <<EOF
>> LABI FP=mFo FC=DFC PHI=PHIC
>> RESO 29.50 3.22
>> SCAL 2.0 -1.0
>> EOF
>>
>> (2)
>> ./omit hklin ${f}.mtz mapout ${f}.map <<EOF
>> LABI FP=FWT FC=FC PHI=PHIC
>> RESO 29.50 3.22
>> SCAL 1.0 0.0
>> EOF
>>
>> The output maps are just different, and I wonder why. I am also more
> concerned about which one is more appropriate for the sigmaa-weighted
> 2mFo-DFc composite omit map.
>>
>> (mFo is what I generated from the SIGMAA output)
>>
>> Thanks for any suggestions!
>>
>> Best Regards, Hailiang
>>
>
>
> Zbyszek Otwinowski
> UT Southwestern Medical Center at Dallas
> 5323 Harry Hines Blvd.
> Dallas, TX 75390-8816
> Tel. 214-645-6385
> Fax. 214-645-6353
>
>
>
> Zbyszek Otwinowski
> UT Southwestern Medical Center at Dallas
> 5323 Harry Hines Blvd.
> Dallas, TX 75390-8816
> Tel. 214-645-6385
> Fax. 214-645-6353
>
>
