nx,ny,nz

int

Dimensions of the image, also available as get_xsize(),etc. Note: Assignments such as e["nx"] = 30 are an (not preferred) alternative to set_size(nx,ny,nz)

minimum

float

Smallest value in the image

maximum

float

Largest value in the image

mean

float

The average pixel value in the image

sigma

float

The standard deviation of the pixel values in the image

square_sum

float

Sum of the squares of the pixel values

mean_nonzero

float

The mean value of all nonzero pixels

sigma_nonzero

float

The standard deviation of the pixels ignoring pixels which are zero

is_complex

int

Flag indicating that the image is complex (R/I or A/P pairs)

is_complex_ri

int

Flag indicating that a complex image is R/I not A/P

changecount

int

An integer which is incremented every time the image is marked as changed

data_path

string

Used only in BDB files, to indicate that the binary data for an image should be read from an alternate location. Data cannot be written back to such objects.

skewness

float

Skewness of the pixel values

kurtosis

float

Kurtosis of the pixel values

median

float

Median value of the pixel values

nonzero_median

float

Median value of nonzero pixels

apix_x,y,z

float

Angstroms per pixel on the x-axis (also _y and _z). If _y or _z are 0 or not present it will be assumed that they are the same as _x. Note that CTF objects have an independent value for A/pix

class_id

int

Set by classification routines to indicate which class number the particle is in

class_ptcl_src

string

In a class-average, this is the file containing the raw images used to create the average

class_ptcl_idxs

tuple

In a class-average, this is a list of particle numbers used in the final average (see class_ptcl_src)

ctf

Ctf subclass

A subclass of Ctf containing all CTF parameters

ctf_phase_flipped

bool

Set to true if the CTF phases have been flipped

ctf_wiener_filtered

bool

Set to true if a Wiener filter has been applied

ctf_snr_total

float list

Set in class-averages by some averagers indicating the total estimated radial SNR of the average

data_path

string

Used for virtual stacks. References binary file and location for image data as file*location

data_source

string

Used in virtual stacks. This is a reference back to the source image from which this image was derived

data_n

ing

Used in virtual stacks. This is the image number

eigval

float

Eigenvalue, only set for images which represent Eigenvectors

exc_class_ptcl_idxs

tuple

In a class-average, this is a list of particle numbers provided to the averager, but excluded from the final average (see class_ptcl_src)

match_n

int

used to represent the number of a reference particle this particle best matched

match_qual

float

used to represent the quality associated with match_n, smaller is a better match

projection_image

string

In a class-average, this represents the image file which was used for initial alignment references

projection_image_idx

string

In a class-average, this represents the specific image number in projection_image

ptcl_repr

int

If an image/volume represents the combination of one or more other images, this is the count of the number of particles that went into the average

ptcl_helix_coords

tuple

The two endpoints and a box width that defines a helix box (x1, y1, x2, y2, box_width)

ptcl_source_coord

tuple

The central coordinate of a boxed particle in terms of its source image, normally (x,y), may be (x,y,z) for subtomograms

ptcl_source_image

string

The name of the image from which the particle was extracted. Full path, may be in bdb syntax

reconstruct_norm

float

Normalization factor applied to a single projection/class-average during reconstruction

reconstruct_qual

float

Quality of a single projection/class-average relative to others during reconstruction. Unlike with comparators, larger values are better.

reconstruct_preproc

bool

Set if the image has been preprocessed for use with a reconstructor

render_min,max

float

Used when rendering an image to 8/16 bit integers. These are the values representing the minimum and maximum integer values

segment_centers

float list

Used when a volume has been segmented into regions. Set of 3*nregions floats in x1,y1,z1,x2,y2,z2,... order, indicating the center of each region as defined by the specific algorithm

source_path

string

When an image is read from a file, this is set to the filename

source_n

string

When an image is read from a file, this is set to the image number

subvolume_x0,y0,z0

int

Used when the EMData stores only a portion of a larger image in certain contexts (notably direct Fourier inversion. This represents the location of the origin of 'this' in the larger virtual volume

subvolume_full_nx,ny,nz

int

Used with subvolume_x0,... Specifies the size of the virtual volume that 'this' is a part of

threed_ptcl_src

string

In a 3-D map, this is the file containing the raw images used to create the reconstruction

threed_ptcl_idxs

tuple

In a 3-D map, this is a list of particle numbers used in the final reconstruction (see threed_ptcl_src)

threed_excl_ptcl_idxs

tuple

In a 3-D map, this is a list of particle numbers excluded from the final map (see threed_ptcl_src)

xform.projection

Transform

A Transform object used by Projectors. It is applied to a 3-D model prior to projecting by summing along Z. The inverse of this Transform is used by Reconstructors

xform.align2d

Transform

A Transform object representing a 2-D transformation used to align this EMData object to a reference in 2-D

xform.align3d

Transform

A Transform object representing a 3-D transformation used to align this (3-D) EMData object to a (3-D) reference

apix_scan

float

Scan pixel size in Angstroms

(there are already parameters for apix_x/y/z above. Is this different in some way ?, you could provide this as supplementary information, but apix_x/y/z remain the 'official' values. Is this what you want ?)

box_location

int_array

4 values, x0, y0, xsize, ysize representing the location of the particle in the original (box_source) image

(Pawel suggested this be changed to the reduced image, because normally we first reduce the micrograph, the window it.) (No, the box location should be in the coordinates of the referenced 'parent' image. If you want to reference a reduced image you can, but I think it makes a lot more sense to provide the capability of refining the coordinates from the reduced image when you return to the original image.) Pawel: the coordinates in boxer refer to the image from windowing was done. This is is (or can be) a reduced micrograph. There is more confusion here: name apix_scan suggests this is pixel size of the scan, NOT THE REDUCED MICROGRAPH FROM WHICH PARTICLES WERE WINDOWED. Incidentally, both pixel sizes are needed and have to be in the header. Steve: This differs from the philosophy of e2boxer, which is that you always provide e2boxer with the original image, it may internally downscale it for boxing, but the final box positions are in terms of the original image. I don't understand why you would want to externally downscale, then have to rescale the coordinates again later ? This is very messy. Anyway, any single image has a particluar A/pix value associated with it. I have no objections to something like apix_original, but what exactly is the point ? You aren't likely to rescale reduced images back to their original size...

box_score

float

A value representing the relative quality (meaning may vary) of this particle compared to others

box_source

string

Filename (not full path) of the image this particle was extracted from

box_source_id

string

Other (database) identifier of the image the raw data came from if available