Dictionaries of Hashtables in MATLAB?

Hi all,

Is there a way to create a hash table or dictionary in MATLAB such that I can retrieve a set of values based on a key?

I also need to append more entries to the end of the list, given a key. I tried importing a hashtable from java.util.Hashtable, but the "add" method overwrites the current entries if a key already exists...

Thanks for all your help!

Answer 1

[Walter Roberson]

Perhaps containers.map ? http://www.mathworks.com/help/matlab/map-containers.html

[Philip]

That looks like it might do the trick, but I can only see how to initialise the map. Have you used this before? Do you know how I can add keys and values one by one? Can the map contain more than one value for a single key?

[Philip]

(I need to collect the keys and values inside a loop, so I don't know them beforehand - this means unfortunately I cannot enter all the data at once.)

[Philip]

To answer my own question there, it seems the solution for adding values without overwriting the previous entries is:

mapName('key_string') = [mapName('key_string') [1 2 3]];

Thanks for your suggestion. I think this will work!

Answer 2

[Mike Croucher]

Reviving this thread in 2022 because R2022b contains a new dictionary data type. A tutorial-like introduction at An introduction to dictionaries (associative arrays) in MATLAB » The MATLAB Blog - MATLAB & Simulink (mathworks.com)