Hi Remi,
This is perfectly fine. We do this often now, also for 3D
classification. Just be careful that the translations in the data.star
file are in pixels (not in Angstroms), and that the magnification
scaling factor is stored in the physical detector pixel size upon
extraction with rescaled particles. This just in case you want to keep
any values from the data.star file after classification of the smaller
particles.
HTH,
S
On 11/24/2014 03:47 PM, Rémi Fronzes wrote:
> Hi Sjors,
>
> We are working on a fairly large protein complex which requires fairly large boxes (about 300 pixels). 2D classification takes ages (several days).
> Since the dataset is fairly clean, I was wondering if it could be possible to scale down the boxes by a factor of 2 and run 2D classification with these down-scaled particles. Then I would extract the particles contained in the good classes and modify the star file generated to point to the original stack rather than the scaled-down particles.
> Is it a valid procedure ? Or I am missing something important to take into account.
>
> Thanks
>
> All the best
>
> Rémi
>
>
> Rémi Fronzes
> G5 biologie structurale de la sécrétion bactérienne, institut Pasteur
> CNRS UMR 3528, institut Pasteur
>
> Office: +33 (0)145688864
> Lab: +33 (0) 145688863
> Mobile: +33 (0) 688263992
> Email: [log in to unmask] <mailto:[log in to unmask]>
>
> 25 rue du Docteur Roux
> Bâtiment Metchnikoff, 3ème étage
> 75015 Paris, France
>
>
--
Sjors Scheres
MRC Laboratory of Molecular Biology
Francis Crick Avenue, Cambridge Biomedical Campus
Cambridge CB2 0QH, U.K.
tel: +44 (0)1223 267061
http://www2.mrc-lmb.cam.ac.uk/groups/scheres
|