= EMAN2 Concepts and Conventions =

=== Data Storage ===
 * [[Eman2DataStorage|File Formats, Data storage conventions]]
 * [[Eman2NFS|Using EMAN2 in environments with NFS or other network-shared directories]]
 * [[Eman2HDF|How EMAN2 stores data in HDF5 files]]
 * [[Eman2Metadata|Parameters/Metadata appearing in EMData attributes (and stored on disk with the image), accessed with get_attr and set_attr]]
 * [[Eman2AppMetadata|Parameters/Metadata for applications, not associated with a specific image, stored in bdb:project]]
 * [[Eman2InfoMetadata|Parameters/Metadata associated with projects stored in the ''info'' folder]]

=== Mathematical Conventions ===
 * [[EMAN2/BoxSize|Particle box-size and refinement speed, what size to use]]
 * [[EMAN2/AngStep|Angular sampling, number of projection and resolution]]
 * [[Eman2TransformInPython|3D and 2D Transformations (rotation, translation, etc.)]]
 * [[EMAN2/Symmetry|Symmetry in EMAN2, and generating projections in an asymmetric unit]]
 * [[EMAN2/CtfModel|CTF model used in EMAN2]]

=== Modular functions in EMAN2 ===
Many aspects of EMAN2 are modular, meaning new functions can be easily added for a variety of tasks. These categories are used in the GUI and from
the command-line, and are not just useful for programmers. For example, the '--process' option in e2proc2d.py and e2proc3d.py uses 'processors' as
defined below.

 * [[EMAN2/Modular/Overview|Overview of how to use modular functions]]
 * [[EMAN2/Modular/Processors|Processors]] - Filters, masks and other basic image processing operations
 * [[EMAN2/Modular/Cmps|Comparators]] (cmp) - Similarity metrics (cmp) for comparing two images/volumes
 * [[EMAN2/Modular/Aligners|Aligners]] - Algorithms for aligning one image/volume to another
 * [[EMAN2/Modular/Averagers|Averagers]] - Methods for averaging many images/volumes together
 * [[EMAN2/Modular/Projectors|Projectors]] - Generate 2-D projections of 3-D volumes (or 1-D projections of 2-D images)
 * [[EMAN2/Modular/Reconstructors|Reconstructors]] - Generate 3-D volumetric reconstructions from sets of 2-D images and orientation paramters
 * [[EMAN2/Modular/Analyzers|Analyzers]] - Perform various analyses on sets of images/volumes
 * [[EMAN2/Modular/Symmetries|Symmetries]] - Permissible symmetries to use in EMAN2
 * [[EMAN2/Modular/OrientGens|Orientation Generators]] (orientgen) - Methods for generating sets of orientations filling an asymmetric unit



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