How can i do the summation of every row?

1 view (last 30 days)
Davide Conti
Davide Conti on 5 Nov 2019
Edited: Guillaume on 6 Nov 2019
Dear Experiences
i have a table that look like the following:
Table (from column 83 to 110):
Name ... 83 84 85 86 87 ..... 110
ID1 1 -1 0 -1 0 -1
ID2 4 2 3 -1 0 -1
ID3 0 -1 2 -1 3 -1
ID4 2 2 2 -1 0 -1
what I want to do is to know how many are the numbers >= 0, in column 111
Name ... 83 84 85 86 87 ..... 110 111
ID1 1 -1 0 -1 0 -1 3
ID2 4 2 3 -1 0 -1 4
ID3 0 -1 2 -1 3 -1 3
ID4 2 2 2 -1 0 -1 4
where the column 111 involve the summation of every independent row,
thanks for any help.
  5 Comments
Guillaume
Guillaume on 6 Nov 2019
Tables don't normally have numerical column names (it's only in the latest R2019b that you can have such names). This is the way a table is displayed in matlab:
>> demotable(1:4, [83:87, 110])
ans =
4×6 table
Var83 Var84 Var85 Var86 Var87 Var110
_____ _____ _____ _____ _____ ______
ID1 3 1 -1 -1 3 1
ID2 1 -1 3 4 1 4
ID3 0 3 0 0 1 1
ID4 -1 -1 2 0 2 4
which is a lot less ambiguous than what you have.
Anyway, I've already shown in my answer how to do what you want in just one line.
As I said, it doesn't look like you're using the features of a table, so perhaps you should be using a matrix, which in this case would be easier to work with.

Sign in to comment.

Answers (2)

JESUS DAVID ARIZA ROYETH
JESUS DAVID ARIZA ROYETH on 5 Nov 2019
replace yourtablename for the real name
value=sum(yourtablename{:,111})
  4 Comments
Guillaume
Guillaume on 5 Nov 2019
Edited: Guillaume on 5 Nov 2019
sorry but it doesn't work and I can't understand why
we'd stand a chance of understanding why if you told us what's happening. If you get an error message then give us the full text of the error message. If you don't get the expected result, what did you get and how did it differ from what you expected.
Why is this cycle wrong?
Because you're overwriting Data{i, 111} at each j. And you're passing a scalar to sum. The sum of a scalar is that scalar.

Sign in to comment.


Guillaume
Guillaume on 5 Nov 2019
Edited: Guillaume on 6 Nov 2019
Guessing at what you're trying to do from your loop code:
Data{:, 111} = sum(Data{:, 83:110} >= 0, 2);
It doesn't look like you're using any feature of a table, so if everything is numeric in your table, you'd be better off storing the data in a matrix. The equivalent matrix syntax of the above is:
yourmatrix(:, 111) = sum(yourmatrix(:, 83:110) >= 0, 2);
slightly edited the answer now that we have clarification of what's needed

Categories

Find more on Tables in Help Center and File Exchange

Community Treasure Hunt

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

Start Hunting!

Translated by