Re: [ccp4bb]: arp warp bad data warning

[Anastassis Perrakis <perrakis@nki.nl>]

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> Arp warp
> seems to be very sure of itself in telling me that
> my low resolution data is bad and I should cutoff at 3.25A (!).  Is it 
> the
> honest truth, or is there something I should know about the usage of 
> arp
> warp?
>
> Does anyone have any commments?
>

.....well. Lets say that this Wilson test tends sometimes to give useless 
suggestions, ie to cut low resolution
at 3.25 A. I would not do that. Being co-responsible for programming 
that suggestion,
please also accept my apologies.

On the other hand, to see it postive (...) such a message 'forces' you 
to look at your data again.
I don't know what that spike is (ice?) but its not a good sign ! And, 
it could explain why
the bulk solvent model explodes or whatever.

I also want to add that NCS tends to 'skew' Wilson statistics and 
ARP/wARP will almost invariably
complain over datasets with NCS because they do not fit Wilson stat 
expectations.

But the 'spike' is another story.

Also remember: At really final stages of refinement, REFMAC5 does the 
job. The ARP/wARP scripts
do nothing but 'wrap' it. It might worth checking things like 'bulk 
solvent' effects in refinement
in REFMAC5 alone.


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