Placing a structure within a map container - or is there a different, more suitable way to store this type of data?

I have some data associated with several "labels" ('Jan','Feb','Mar', for example), and for each of these labels there are multiple data types (numeric arrays, strings, datetime, etc) for each.

I would like to access the data by specifying the label itself, so I don't have to keep track of any integer indices. I have recently discovered map containers, and tried to implement it in this case by using my "labels" as the keys in the map:

keys = {'Jan','Feb','Mar'};
data_map = containers.Map('KeyType','char','ValueType','any');

% loop over keys and put some data in the map
for k = 1:length(keys)
    
    data_struct.prices = rand(1,5);   % create some dummy numbers
    data_struct.description = 'HIGH'; % create a dummy label
    
    % place the structure in the map at the relevant key
    data_map(keys{k}) = data_struct; 
    
    % delete ready for next iteration of the loop
    clear data_struct
end

This works nicely, because the structure object is able to handle all the different data types, and I can very compactly and nicely access my data without any integers using:

data_map('Feb').description

My Problem

1) I feel like I am not using it in the correct way, because I have had to use the temporary structure data_struct inside the loop.

2) Additionally, later on I would now like to add an extra field to the structure associated with one of the keys, and would ideally do something like the following for example:

data_map('Feb').temperature = rand(1,8);

This gives the following error:

Only one level of indexing is supported by a containers.Map.

The only way I have been able to do it is to create a temporary structure, which is ugly and cumbersome:

temp_struct = data_map('Feb');
temp_struct.temperature = rand(1,8);
data_map('Feb') = temp_struct;
clear temp_struct
disp( data_map('Feb').temperature )

Is there a better way to store this type of data, append to it afterwards, and still access it nicely by a key name?

Answer 1

[teeeeee]

Thanks to Sindar for the suggestion of using tables. I have since become aware of an alternative way to do this, which I think is worth showing as a seperate answer for reference.

This way allows to omit completely any temporary struct variables (as does Sindar's method), but I think is a litlte easier to think how the data is organised:

keys = {'Jan','Feb','Mar'};
data_map = containers.Map('KeyType','char','ValueType','any');

% loop over keys and put some data in the map
for k = 1:length(keys)

    % Define some dummy variables
    prices = rand(1,6);   % a numeric array variable type
    description = 'HIGH'; % a character array variable type

    % Associate a structure with each key, with variables attached to the various fields 
    data_map(keys{k}) = struct('prices',prices,...
                               'description',description);
end

% Add a new field, temperature, to the struct object associated with the key 'Feb'
temperature = rand(1,2);
data_map('Feb') = setfield(data_map('Feb'),'temperature',temperature);

This yields the following for the 'Feb' key for example:

data_map('Feb')

%  struct with fields:

%         prices: [0.9237 0.6537 0.9326 0.1635 0.9211 0.7947]
%    description: 'HIGH'
%    temperature: [0.7673 0.6712]

And allows me to nicely access the data with the simple commands:

data_map('Feb').prices
data_map('Feb').description
data_map('Feb').temperature

Answer 2

[Sindar]

You can give tables row names so they are indexible that way:

keys = {'Jan','Feb','Mar'};
n_keys = length(keys);
data_table = table(rand(n_keys,5),repmat('HIGH',[n_keys 1]),'VariableNames',{'prices';'description'},'RowNames',keys);
>> data_table('Jan',:)

ans =

  1×2 table

                                   prices                             description
           _______________________________________________________    ___________

    Jan    0.70605    0.046171     0.69483    0.034446     0.76552       HIGH    
>> data_table{'Jan','description'}

ans =

    'HIGH'

[teeeeee]

Thanks for the answer. I hadn't considered doing it with tables. I have also provided an alternative way to do it in a separate answer. It seems a little unusual (at least to me) to have a long vector running horizontally within a single table column (as you have done with "prices"). However, it does the job. Thanks again.