ListTools - Maple Help

Online Help

All Products    Maple    MapleSim


Home : Support : Online Help : Programming : Data Types : Tables, lists, and sets : ListTools Package : ListTools/MakeUnique

ListTools

  

MakeUnique

  

remove copies of elements from a list

 

Calling Sequence

Parameters

Description

Examples

Calling Sequence

MakeUnique(L, N, f, opt1, opt2, ...)

Parameters

L

-

list

N

-

(optional) non-negative integer or infinity

f

-

(optional) procedure

opt1, opt2

-

(optional) extra arguments to procedure f

Description

• 

The MakeUnique(L) function removes all repeated elements from the list L.

  

The elements are reviewed in order from left to right. If an element matches a previous element, it is removed from the list.

  

The order of the elements in the returned list matches the order in the list L.

• 

The MakeUnique(L, N) function retains N copies of matching elements in list L. If greater than N matching elements exist in L, they are removed.

• 

By default, the elements in the list are compared by using boolean comparison. If argument f is specified, then f(x, y, opt1, opt2, ...) is called to check if element x and element y should be considered equal. This function should implement an equivalence relation (i.e. it should be reflexive, commutative, and transitive).  If it is not, then the result may not be valid.

Examples

withListTools:

L1,2,3,4,3,2,3,4,5,4,3,4,5,6

L:=1,2,3,4,3,2,3,4,5,4,3,4,5,6

(1)

MakeUniqueL

1,2,3,4,5,6

(2)

MakeUniqueL,0

(3)

MakeUniqueL,2

1,2,3,4,3,2,4,5,5,6

(4)

MakeUniqueL,'∞'

1,2,3,4,3,2,3,4,5,4,3,4,5,6

(5)

L0.,x1x+1,0.,x21,0,1xx+1

L:=0.,x1x+1,0.,x21,0,1xx+1

(6)

MakeUniqueL

0.,x1x+1,0.,x21,0,1xx+1

(7)

MakeUniqueL,1,verify,expand

0.,x1x+1

(8)

ListTools:-MakeUnique([1,2,6,5,10,9,7,3,11],
                      2,
                      proc(a,b)
                          evalb(a-b mod 4 = 0);
                      end proc
                     );

1,2,6,5,7,3

(9)

See Also

list

ListTools

ListTools[FindRepetitions]

type[list]

verify

 


Download Help Document

Was this information helpful?



Please add your Comment (Optional)
E-mail Address (Optional)
What is ? This question helps us to combat spam