Well - the old way to estimate sigma was Sqrt(I**2 +
constant_representing background) and then get
Sigma_F as ~ sqrt(SigI)/(2*F ) .
sftools would calculate that for you and append it to the output file..
Eleanor
Eleanor Peter Adrian Meyer wrote:
>> I add a fake "sigma" column for each "data" column because so many
>>
> programs require one.
>
> This is slightly tangential, but does anyone know of a good way to
> generate semi-realistic sigma values for calculated/simulated data?
>
> The best I've been able to do is borrow from an experimental dataset of
> the same protein (after scaling), but that doesn't work unless you've got
> an experimental dataset corresponding to your simulated one. I also tried
> a least-squares fit (following a reference I don't have in front of
> me...this was a while ago), which didn't result in a good fit for our
> data.
>
> Pete
>
> Pete Meyer
> Fu Lab
> BMCB grad student
> Cornell University
>
>
>
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