Thank you all for the information and F estimator write-up.
With regards
Karthik
On 13-03-2017 03:56 AM, Phil Evans wrote:
Sorry Ian, I was attributing this to Kevin
apologies
Phil
On 12 Mar 2017, at 21:56, Ian Tickle <ianj...@gmail.com> wrote:
Eleanor,
Phil is right about the bias of the weighted mean, here's how I do it using a
minimum mean-squared error estimator which seems to give more accurate results
than either the unweighted or the weighted mean:
http://staraniso.globalphasing.org/Optimal-F-estimator.pdf
This is actually about Fmean but the same applies to Imean.
This actually only makes a significant difference to the result if there's a
big difference between sd(I+) and sd(I-), which is obviously not very common.
Cheers
-- Ian
On 12 March 2017 at 17:58, Eleanor Dodson <eleanor.dod...@york.ac.uk> wrote:
You read:
h k l IPLUS SIGIPLUS INEG SIGINEG
Then program calculates this:
SIGIMEAN = SIGIPLUS*SIGINEG/(SIGIPLUS+SIGINEG)
IMEAN = (IPLUS/SIGIPLUS + INEG/SIGINEG)*SIGIMEAN
ie: IMEAN = ( IPLUS*SIGINEG + INEG * SIGIPLUS ) / /(SIGIPLUS+SIGINEG)
Is that the right thing to do? Not sure!
Eleanor Dodson
On 11 March 2017 at 15:18, Karthikeyan Subramanian <skarthi...@gmail.com> wrote:
Dear CCP4bb,
How IMEAN and SIGIMEAN is calculated in scalepack2mtz if the input is with
anomalous intensity (obtained from HKL2000). Any guide/reference is highly
appreciated.
Thanks in advance,
With regards
Karthikeyan S.
Principal Scientist
IMTECH, Chandigarh
