How to assign strings and numbers to elements of the same matrix?

I want to write the word "average" in the 5 element, first row on my matrix and I want to write numbers 1 to 3 into the second to fourth elements. But I am using wrong syntax:

ResultMtx(2:5,1) = [1; 2; 3; "average"];

How can I write this correctly? Thank you.

Answer 1

[Walter Roberson]

[1; 2; 3; "average"]

The first part of that, the 1; 2; 3, is establishing a numeric array -- in particular a double precision array.

The last part of that, the "average", is a string() scalar.

MATLAB cannot store string() scalars inside a numeric array. MATLAB numeric arrays do not store the datatype of each element separately: numeric arrays only store a single datatype that applies to the entire array.

You can create a cell array,

ResultMatx = num2cell(ResultMatx);
ResultMatx(2:5,1) = {1; 2; 3; "average"};

cell arrays can have a different datatype for each element. But you might not like the formatting for displaying them.

[Hannah]

Thank you for your explanation! :) I did not know that Matlab arrays only store a single datatype that applies to the entire array. That's quite unfortunate for what I wanted to do because I needed to write numeric values in other elemnets of matrix therefore I can't have an only string supporting matrix :( Is there perhaps a way to leave an element in that double precision array as empty (I don't mean 'nan') so that I manually write the string into excel myself and not have it over-written?

[Walter Roberson]

I recommend you use cell arrays, and use writecell(), provided that your MATLAB is new enough to have writecell()

data = randi(9, 6, 1)

data = 6×1

4 3 8 8 1 7

datacell = num2cell(data);
datacell{end-1,1} = "average";
datacell{end,1} = mean(cell2mat(datacell(1:end-2,:)))

datacell = 6×1 cell array
    {[        4]}
    {[        3]}
    {[        8]}
    {[        8]}
    {["average"]}
    {[   5.7500]}

[Walter Roberson]

You could also use a numeric array and put NaN values, and then later ask to writecell into that particular location in the existing table. This is not efficient, as it requires a separate writecell() for each text written into an otherwise numeric column (though adjacent items could be merged into one call.)

Answer 2

[Steven Lord]

Do you need your data stored with mixed-type columns or would mixed-type rows work? If the latter, consider a table array.

ResultTbl = table(1, 2, 3, "average")

ResultTbl = 1×4 table
    Var1    Var2    Var3      Var4   
    ____    ____    ____    _________

     1       2       3      "average"

scores = ResultTbl{1, 1:3}

scores = 1×3

1 2 3

assessment = ResultTbl.Var4

assessment = "average"

[Walter Roberson]

If I understand correctly, user is looking to store the results into Excel, not unlike the way it is common for people to have spreadsheets that say things like

Jan     5
Feb     2
Mar    -4
Apr     7
total ====
       10

[Hassan Bahy]

mr Walter Roberson could you help me to create a table consist of multi rows with two column the first column from data type string & second column is numbers, could you help me sir,please