Command Reference : Matrix Language Reference
  
 
@dupsid
Syntax: @dupsid(A1[, A2,...])
Argument 1: vector or matrix, A1
Argument 2+: (optional) vector or matrix, A2,...
Return: vector
Returns a vector of group IDs identifying unique/duplicated row data. The IDs for two rows are identical if and only if the values of vectors or matrices A1, A2, etc., are identical for both rows.
See also @dupsobs and @dupselem.