 For extracting eigencomponents from random vectors or matrices , a complex moment forms a filter that allows desired eigencomponents to pass through.
<meaning-changed>  For extracting eigencomponents from random vectors or matrices , a complex moment forms a filter that allows desired eigencomponents to pass through.
 A complex moment plays the role of a filter and extracts eigencomponents of interest from random vectors or matrices , a complex moment forms a filter that allows desired eigencomponents to pass through.