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Is there an efficient way to calculate hash for objects

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Hey,
I have objects ("Sequence") on which I need to do some heavy calculations, the result is another object of the same kind (a different, fixed, "Sequence").
These calculations are often repeated, so I want to save the results in a Map, such that they will only be done once (for each Sequence).
The problem: The keys for the map have to be numbers or strings...
Is there any Efficient way to calculate some sort of unique Hash for an object?
I've seen Datahash, but it seems to be for structs...
If it matters, "Sequence" contains only a single property: a cell array of "Pulse" (another object). "Pulse" has several primitive properties and a struct.
Small clarification, I need the hash to be the same for different handles if internal structs are the same (same as isequal, and not as ==).
For example:
a = Sequence() % Default constructor
b = Sequence() % Default constructor
Hash(a) == Hash(b) % Should be true
Of course, I can calculate some sort of hash myself, but I wonder if there is some other way which might be more efficient...

Accepted Answer

Ameer Hamza
Ameer Hamza on 27 Apr 2020
Have a look at the memorized function: https://www.mathworks.com/help/matlab/ref/memoizedfunction.html. This might be helpful. The submission by Jan, you linked in your question, will also work for objects, not just structs. You may also want to have a look at jsonencode(): https://www.mathworks.com/help/matlab/ref/jsonencode.html
  7 Comments
Alan Frankel
Alan Frankel on 20 Jun 2024
Folks: please note the difference between the words "memorized" and "memoized" (no "r"). The name of the function is "MemoizedFunction".
Yoav Romach
Yoav Romach on 21 Jun 2024
Coming back to a question that was answered 4 years ago to comment about a typo in a function that wasn't used for the solution. So helpful, thanks.

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