***  For details on how to be removed from this list visit the  ***
***          CCP4 home page http://www.ccp4.ac.uk         ***




> The problem with an anomalous signal-to-noise ratio of 1 is that you
> can't tell if you got anything just by looking at the data.  That is, if
> you have no signal at all you still expect your DANOs to have an average
> value that is equal to the average value of SIGDANO.  However, the
> signal does tend to be stronger for low-angle data.  The "DelAnom
> correlation between half-sets" analysis done by SCALA does appear to be
> a good way of detecting pretty weak anomalous signals.  I highly
> recommend that you look at it.

Why would the anomalous signal be stronger for low-angle data?  f'' (as I
understand it) is roughly constant with respect to scattering angle
(resolution), while f0 falls off rapidly with increasing scattering angle.
 delta f' (for anomalous) should behave similiarly.

Am I missing something here?

Pete

Pete Meyer
Fu Lab
BMCB grad student
Cornell University

Reply via email to