Re: [ccp4bb]: sftools and HL coefficients

[Bart Hazes <bhazes@ualberta.ca>]

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On Wed, 29 Aug 2001, Qian Xu wrote:

> Dear all,
>
> I am using sftools to add 4 sets of HL coeffs (from 4 derivatives)
> together. These 4 sets have different resolution ranges. I found the
> resulting coeffs can only be in the lowest resolution range due to the
> absent data. So how can I make use of those higher resolution coeffs not
> present in all 4 derivatives in order to get the phase with higher
> resolution? Thanks in advance.
>
> Qian

When there is a missing number flag (MNF) in a calculation SFTOOLS will return
a MNF as the result of the calculation for that reflection. Most of the time
that is the only sensible thing to do. In your particular case if there are
MNFs for one derivative you still want to use the others. To fake this you can
do the following for each derivative

select col 3 absent
calc col 3 = 0
calc col 4 = 0
calc col 5 = 0
calc col 6 = 0
select all

(assuming your HL coefficients are in columns 3 to 6)

This should have set all the MNFs for this derivative to zero.
(use CHECKHKL to make sure there are no more MNFs).

After you have done this for all derivatives you can add all the HL
coefficients. The missing ones will be added as zeroes and thus not affect the
result.

Bart

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