;+ ; NAME: ; NONUNIQ ; ; PURPOSE: ; Return the subscripts of the non-unique elements in an array. ; ; Note that repeated elements must be adjacent in order to be ; found. This routine is intended to be used with the SORT ; function. See the discussion of the IDX argument below. ; ; This function is a simple modification of IDL's uniq function. ; ; CATEGORY: ; Array ; ; CALLING SEQUENCE: ; UNIQ(Array [, Idx]) ; ; INPUTS: ; Array: The array to be scanned. The type and number of dimensions ; of the array are not important. The array must be sorted ; into monotonic order unless the optional parameter Idx is ; supplied. ; ; OPTIONAL INPUT PARAMETERS: ; IDX: This optional parameter is an array of indices into Array ; that order the elements into monotonic order. ; That is, the expression: ; ; Array(Idx) ; ; yields an array in which the elements of Array are ; rearranged into monotonic order. If the array is not ; already in monotonic order, use the command: ; ; UNIQ(Array, SORT(Array)) ; ; The expression below finds the non-unique elements of an unsorted ; array: ; ; Array(UNIQ(Array, SORT(Array))) ; ; OUTPUTS: ; An array of indicies into ARRAY is returned. The expression: ; ; ARRAY(UNIQ(ARRAY)) ; ; will be a copy of the sorted Array with non-duplicate adjacent ; elements removed. ; ; COMMON BLOCKS: ; None. ; ; MODIFICATION HISTORY: ; Written by Edward C. Wiebe, 2002-07-23 (Modified IDL's ; uniq.pro into nonuniq.pro - so this was really written by RSI) ; ;- ; function NONUNIQ, ARRAY, IDX ; Check the arguments. s = size(ARRAY) if (s[0] eq 0) then return, 0 ;A scalar if n_params() ge 2 then begin ;IDX supplied? q = array[idx] indices = where(q eq shift(q,-1), count) if (count GT 0) then return, idx[indices] $ else return, n_elements(q)-1 endif else begin indices = where(array eq shift(array, -1), count) if (count GT 0) then return, indices $ else return, n_elements(ARRAY)-1 endelse end