Assign a value to a dictionary of dictionary

Hello everyone,

I have something like:

x = dictionary(dictionary()); % creating dictionary of dictionary
x_1 = dictionary; % creating a dictionary to map to x
x_1({[1,2,3]}) = 5; % assigning a cell as key and 5 as value
x(1) = x_1; % mapping 1 as key and x_1 as value to x

Now when I want to map something to the dictionary of x(1) how to perform it?

Something like this:

x(1)({[1,3,4]}) = 6; % this errors

But I am not able do something like this because of indexing issues

So I tried:

x_1 = x(1);
x_1({[1,3,4]}) = 6;
x(1) = x_1;

But this seems like a lot of time wasted, by making a copy of x(1) to x_1, and then performing the operation and mapping it back. Is there any better way to do this?

Thanks in advance!

Answer 1

[chicken vector]

The impossibility of multiple indexing is a remarkable limitation that has also been discussed on the forum.

Unfortunately, I don't think there is an answer that might completely satisfy our needs of brevity.

A workaround for when you have only two layers of dictionaries is to use cells:

x = dictionary;
x_1 = dictionary;
x_1({[1,2,3]}) = 5;
x(1) = {x_1};

x{1}({[1,2,3]})

ans = 5

Otherwise you can use function handles for an indefinite number of subdictionaries:

getValue = @(dict,key) dict(key);
x = dictionary;
x_1 = dictionary;
x_1({[1,2,3]}) = 5;
x(1) = x_1;

getValue(getValue(x,1),{[1,2,3]})

ans = 5

[Ajay Reddy]

Thanks a lot! It helped

[chicken vector]

Glad it did