AS F - Average images - find statistics & Q factor map ||

(06/07/99)

PURPOSE

Adds a series of images representing single, aligned particles or patches of a crystal lattice, and computes a Q factor map. Images have to have even dimensions (internally FFT is used).   Example.

SEE ALSO

AS R [Average image/volume series, optional subset]

USAGE

.OPERATION: AS F

.FILE PREFIX OR TEMPLATE (EG. PIC****): IMA***
[Enter the template for the image file series.]

.FILE NUMBERS: 1-10,19-78
[Image file numbers to be used.]

.AVERAGE FILE: AVA001
[Enter the name of the output file where the average of the image series is to be written.]

.Q FACTOR FILE: QFA001
[Enter the name of the file where the Q factor map (= Q factor computed at each point of the reciprocal lattice) is to be put.]

.INDICES FOR VECTOR LISTING: 2, 2
[A single reflection may be specified for which the cumulative Q factor is calculated and listed in the DOCUMENT file as a function of the number of transforms added. Enter <CR> or 0, 0 if you do not wish to use this option.]

If non-zero indices were entered in the previous line SPIDER will ask:

.DOCUMENT FILE: DOC001
[Enter document file name which will contain the cumulative Q factor for the Fourier coefficient chosen.]

NOTES

  1. The theory of the Q factor analysis can be found in the following texts:

  2. M.Kessel, M.Radermacher, J.Frank. The structure of the stalk layer of a brine pond microorganism: correlation averaging applied to a double layered structure. Journal of Microscopy, vol.139, pt.1, July 1985, pp.63-74.

  3. M. van Heel, J. Hollenberg. On the stretching of distorted images of two-dimensional crystals. Electron Microscopy at Molecular Dimensions (eds.: W. Baumeister and W. Vogell), pp. 256-260,. Springer, Heidelberg, 1980.

  4. K.V. Mardia. Statistics of Directional Data. Academic Press, London, 1972.

  5. Implemented by: Paul Penczek.

SUBROUTINES

QFACT, QFACT_P

CALLER

UTIL2

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