Dear Bill,,

On Sun, Oct 26, 2008 at 07:18:05PM -0700, William G. Scott wrote:
> I'm actually one of those whom has struggled unsuccessfully to install 
> Sharp.  I can't even remember why, and I am certain it was entirely my 
> fault, but this did get me wondering...

I guess this is often a more general problem: when we're dealing with
a crystallographic problem that our current set of practices doesn't
deal satisfactorily with and we would like to try out another program,
this is usually also a time of great stress and pressure (competitors,
supervisors, finishing PhD etc). Ideally one would want to install and
learn how to use a new software package when there is a half day or
day time ... seldom happens.

Without getting into details of installation, usually (> 90%) it is
enough to download our packages and then run "./installSHARP -F". I
might be wrong - but this could be a problem of not getting enough
feedback about failed attempts (time pressure?). So please tell us
about installation problems (or any problems) - hopefully this is a
small price to pay for getting the software for free. If you feel like
sending us positive feedback - even better (especially since
crystallographic software doesn't get citations anymore these days
... maybe hidden in supplementary material that isn't easily visible
through any search system I know of).

> mlphare and MIR/MAD phasing seems to me the weak point in the ccp4 
> distribution. (I've often switched over to CNS to calculate phases and 
> solvent-flatten them.)
>
> Is there any chance your team might be inspired, persuaded or bribed to 
> create a drop-in replacement for mlphare, maybe a "sharp light" for 
> boneheads like me? Something that uses the same I/O and interface as ccp4?

A drop-in replacement would be very tricky: the concepts of SHARP are
quite different (there is no such thing as 'native' or 'derivative') -
but this adds a huge amount of flexibility.

However, in the next 6.1 release there will be a autoSHARP CCP4i
interface already in the CCP4 distribution (it's already there in the
latest 6.0.99 prerelease or the CVS sources). Although this will still
require the installation of SHARP/autoSHARP itself, at least one could
run autoSHARP without the need of running a httpd. But be aware that
using the CCP4i interface does limit you somewhat - a lot of the
additional tools (regarding density modification, checking/finding
sites via LLG maps, fine-tuning SHARP and viewing maps directly)
aren't easily accessible this way.

But autoSHARP should deal with all the situations that mlphare etc are
dealing with: SIRAS, SAD, MIRAS, MAD etc. And if you want to do (or
need to do) MAD+native+derivative or TaBr-cluster phasing or
site-specific radiation damage or other more complex phasing
scenarios: SHARP itself is the tool for doing all that.

Cheers

Clemens

-- 

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* Clemens Vonrhein, Ph.D.     vonrhein AT GlobalPhasing DOT com
*
*  Global Phasing Ltd.
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*  Cambridge CB3 0AX, UK
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