Macaulay2 » Documentation
Packages » Macaulay2Doc :: unique
next | previous | forward | backward | up | index | toc

unique -- eliminate duplicates from a list



The output list maintains the order of elements in L.

i1 : unique {3,2,1,3,2,4,a,3,2,3,-2,1,2,4}

o1 = {3, 2, 1, 4, a, -2}

o1 : List

Another way to list the unique elements of L is by creating a set from L and then listing its elements. This may be slightly faster than unique, but forgets the ordering of L.

i2 : toList set {3,2,1,3,2,4,a,3,2,3,-2,1,2,4}

o2 = {1, 2, 3, 4, -2, a}

o2 : List

To count occurrences of each element, use tally. To create a sorted list, see sort. For an overview of lists and sequences, see lists and sequences.

See also

Ways to use unique :

For the programmer

The object unique is a method function with a single argument.