Effacer les filtres
Effacer les filtres

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

44 vues (au cours des 30 derniers jours)
Hannah le 9 Sep 2021
Commenté : Hassan Bahy le 20 Nov 2021
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.

Réponse acceptée

Walter Roberson
Walter Roberson le 9 Sep 2021
[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.
  3 commentaires
Walter Roberson
Walter Roberson le 9 Sep 2021
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
Walter Roberson le 9 Sep 2021
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.)

Connectez-vous pour commenter.

Plus de réponses (1)

Steven Lord
Steven Lord le 9 Sep 2021
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"
  2 commentaires
Walter Roberson
Walter Roberson le 9 Sep 2021
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 ====
Hassan Bahy
Hassan Bahy le 20 Nov 2021
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

Connectez-vous pour commenter.


En savoir plus sur Characters and Strings dans Help Center et File Exchange

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by