Difference between revisions of "Cross correlation matrix"
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(Created page with "Category:classification Category:PCA The cross correlation matrix (often called ''ccmatrix'' in ''Dynamo'' jargon) of a set of ''N'' particles is an ''N X N'' matrix....") |
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This similarity of particles ''i'' and ''j'' measured in terms of the normalized cross correlation of the the two aligned particles, filtered to their common fourier components, and restricted to a region in direct space (indicated by a classification mask). The pseudo code will run as: | This similarity of particles ''i'' and ''j'' measured in terms of the normalized cross correlation of the the two aligned particles, filtered to their common fourier components, and restricted to a region in direct space (indicated by a classification mask). The pseudo code will run as: | ||
<code> | <code> | ||
| − | + | ||
| − | + | # read particle i -> Pi | |
| − | + | ||
| − | + | # rotate and shift particles ''i'' | |
| − | + | ||
| + | # create the missing wedge of particle | ||
| + | # rotate missing wedge of particles ''i'' ''RiWi'' | ||
| + | # compute Fourier coefficients common to Cij | ||
</code> | </code> | ||
Revision as of 10:35, 19 April 2016
The cross correlation matrix (often called ccmatrix in Dynamo jargon) of a set of N particles is an N X N matrix. Each entry (i,j) represents the similarity of particles i and j in the data set.
Contents
Definition of similarity
This similarity of particles i and j measured in terms of the normalized cross correlation of the the two aligned particles, filtered to their common fourier components, and restricted to a region in direct space (indicated by a classification mask). The pseudo code will run as:
- read particle i -> Pi
- rotate and shift particles i
- create the missing wedge of particle
- rotate missing wedge of particles i RiWi
- compute Fourier coefficients common to Cij
