EC CLOSE - Extract Connected Clusters - merge close clusters

PURPOSE

Merges neighboring clusters of voxels in a 3D volume into a single "object" or lower hierarchical-level cluster.
Reads a SPIDER document file containing cluster centers of mass. Determines distances between all clusters. If the distance between two clusters is less than the solicited threshold, it sets higher-numbered cluster voxels to the same number as the lower-numbered cluster.

SEE ALSO

EC SELECT	[Extract Connected Clusters - Selection]
EC CL	[Extract Connected Clusters]
EC FILTER	[Extract Connected Clusters - Filter]
EC STAT	[Extract Connected Clusters - Statistics]

USAGE

.OPERATION: EC CLOSE

.CENTER-OF-MASS DOC FILE: doc003
[Contains cluster numbers and centers of masses. Usually prepared using operation 'EC STAT'.]

.ENTER THRESHOLD AND STARTING CLUSTER: 15, 2
[Clusters closer together than specified threshold distance are given same cluster number. Clusters below the starting cluster are ignored.]

.CLUSTER INPUT FILE: VVV001
[Usually a cluster file produced by running 'EC CL'.]

.CLUSTER OUTPUT FILE: VVV002
[Contains remapped cluster numbers.]

NOTES

1. Document files have same format as 'EC STAT' output:
   
   Index key = cluster number + 1
   First register = number of voxels in the cluster
   Next 3 registers = X,Y, and Z center of mass of cluster.

SUBROUTINES

MAPDIST, MAKTAB, MAPIM

CALLER

UTIL6