You can't go to a larger grid without decreasing the resolution of
the map first. If you have a 1 A resolution map and sample it with a
2 A spacing you are not likely to get anything useful (Your FFT
program should complain mightily too). If you cut the resolution to
4 A and sample at 2 you might have some hope.
You can cut the resolution in Coot when you turn on expert mode.
The sampling rate in Coot is a function of the resolution so you should
automatically drop to a courser grid when you cut the resolution.
Dale Tronrud
On 12/05/2013 10:47 AM, Roberts, Sue A - (suer) wrote:
> How about calculating the maps using a larger grid size? You'll lose some detail, but if you're looking at 120 A slabs you're probably not looking at individual atoms/residues anyway. I'm not sure if you can do that in coot or whether you need to calculate the map using ccp4 (or some other program) and read in the map.
>
> Sue
>
> On Dec 5, 2013, at 11:16 AM, Francis Reyes wrote:
>
>> Hi all
>>
>> So I'm running into a case where I need to see maps for large radii (in excess of 120A) and I'm thinking I need to move to bigger hardware than this laptop. Essentially, I'm getting errors in malloc
>>
>> coot-real(85522,0xa062e1a8) malloc: *** mach_vm_map(size=1140850688) failed (error code=3)
>> *** error: can't allocate region
>> *** set a breakpoint in malloc_error_break to debug
>> libc++abi.dylib: terminating with uncaught exception of type std::bad_alloc: std::bad_alloc
>> /Applications/ccp4-6.4.0/bin/../coot.app/Contents/coot/bin/coot: line 251: 85522 Abort trap: 6 $coot_real $@
>> /Applications/ccp4-6.4.0/bin/../coot.app/Contents/coot/bin/coot: line 257: /Applications/ccp4-6.4.0/bin/../coot.app/Contents/coot/bin/guile: No such file or directory
>>
>> What should I look for in a higher end machine? More system memory? Video memory? All of the above?
>>
>> Thanks
>>
>> F
>
> Dr. Sue A. Roberts
> Dept. of Chemistry and Biochemistry
> University of Arizona
> 1041 E. Lowell St., Tucson, AZ 85721
> Phone: 520 621 8171 or 520 621 4168
> [log in to unmask]
> http://www.cbc.arizona.edu/xray or
> http://www.cbc.arizona.edu/facilities/x-ray_diffraction
>
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