MATLAB linked list

data structureslinked listMATLAB

What are some possible ways to implement a linked list in MATLAB?

Note: I am asking this question for pedagogical value, not practical value. I realize that if you're actually rolling your own linked list in MATLAB, you're probably doing something wrong. However, I'm a TA for a class that is MATLAB-intensive this semester, and my goal in asking this question is to understand the general structure of the language better. As MATLAB's general purpose programming facilities are a bit unusual, I feel a question like this will help me understand them.

Best Answer

MATLAB has access to Java:

>> a=java.util.LinkedList;
>> li=a.listIterator;
>> li.add(2);
>> li.add(int8(77));
>> li.add(77);
>> li.add(boolean(true));
>> li.add('Mr. Bill');
>> li.previous();
>> li.add([1 2 3 4 5]);
>> a

a =

[2.0, 77, 77.0, true, [D@66a917, Mr. Bill]

>> a.get(4)

ans =

     1
     2
     3
     4
     5

The one downside of this approach is because MATLAB doesn't have a way to marshal or serialize arbitrary MATLAB objects into Java, you're limited to floating point numbers, integers (need to cast them in MATLAB using int8 etc.), booleans, strings, arrays, and Java objects.

Related Solutions

Python – How to sort a list of dictionaries by a value of the dictionary

The sorted() function takes a key= parameter

newlist = sorted(list_to_be_sorted, key=lambda d: d['name'])

Alternatively, you can use operator.itemgetter instead of defining the function yourself

from operator import itemgetter
newlist = sorted(list_to_be_sorted, key=itemgetter('name'))

For completeness, add reverse=True to sort in descending order

newlist = sorted(list_to_be_sorted, key=itemgetter('name'), reverse=True)

Array versus linked-list

Another good reason is that linked lists lend themselves nicely to efficient multi-threaded implementations. The reason for this is that changes tend to be local - affecting only a pointer or two for insert and remove at a localized part of the data structure. So, you can have many threads working on the same linked list. Even more, it's possible to create lock-free versions using CAS-type operations and avoid heavy-weight locks altogether.

With a linked list, iterators can also traverse the list while modifications are occurring. In the optimistic case where modifications don't collide, iterators can continue without contention.

With an array, any change that modifies the size of the array is likely to require locking a large portion of the array and in fact, it's rare that this is done without a global lock across the whole array so modifications become stop the world affairs.

Best Answer

Related Solutions

Python – How to sort a list of dictionaries by a value of the dictionary

Array versus linked-list

Related Topic