CODEWITHSUNDEEP
arraysmatlabcellvariable-types
00koeffers
00koeffers

Reputation: 327

Convert cell of strings into column of table in MATLAB

I try to use a vector as a column in a table (in MATLAB). However, I always get different errors. Below is a reproducible example, together with the recieved errors:

% What I have:
my_table = array2table(NaN(5, 3));
my_table.Properties.VariableNames = {'col_1' 'col_2' 'col_3'};
my_cell = {'a', 'b', 'c', 'd', 'e'};

% What I tried:
my_table.col_3 = my_cell; %Error: To assign to or create a variable in a table, the number of rows must match the height of the table.
my_table.col_3(1:5) = my_cell; %Error: Conversion to double from cell is not possible.
my_table.col_3.Properties.VariableTypes = {'string'}; %Error: Unable to perform assignment because dot indexing is not supported for variables of this type.

How can I solve this task?

Upvotes: 1

Views: 1133

Answers (2)

Ander Biguri
Ander Biguri

Reputation: 35525

The following works:

my_table.col_3 = my_cell';
% or maybe you prefer
my_table.col_3 = cell2mat(my_cell)';

Let's analyze your problems:

  1. Your sizes are wrong, you just need to transpose the input, from a row to a column!

  2. As it says, you can not directly convert from cell to something else implicitly. cell2mat is a way of doing it.

  3. There is no such thing as my_table.col_3.Properties so MATLAB gets confused and thinks you are doing something else with that dot ..

Upvotes: 1

obchardon
obchardon

Reputation: 10792

If you want to keep the cell type you could use:

my_table.col_3 = my_cell.'

Advantage: You can store more than one character in each row.

Why my_table.col_3 = my_cell doesn't work:

%size(my_table.col_3) = 5x1
%                       ↕ ↕
%size(my_cell)        = 1x5

As you can see above, the size of the first dimension of your cell array does not match with the size of the first dimension of you table. So you can simply permute the dimension of your cell with .'

So now:

%size(my_table.col_3) = 5x1
%                       ↕ ↕
%size(my_cell.')      = 5x1

And matlab (and you) is/are happy.

Upvotes: 2

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