I have a timetable with 10 columns that are all binary and I want to add them together so I get a sum of those binary numbers for each row. Is there an easy way to do this?

0 1 0 0 1 0 1 0 1 1

0 1 0 0 1 0 1 0 1 1

0 1 0 0 1 0 1 0 1 1

0 1 0 0 1 0 1 0 1 1

0 1 0 0 1 0 1 0 1 1

0 1 0 0 1 0 1 0 1 1

0 1 0 0 1 0 1 0 1 1

0 1 0 0 1 0 1 0 1 1

0 1 0 0 1 0 1 0 1 1

0 1 0 0 1 0 1 0 1 1

0 1 0 0 1 0 1 0 1 1

0 1 0 0 1 0 1 0 1 1

0 1 0 0 1 0 1 0 1 1

0 1 0 0 1 0 1 0 1 1

0 1 0 0 1 0 1 0 1 1

this is a copy and paste of the timetable, but it has nearly 2 million rows so I want to find an easy way to do this! Thanks in advance.

[Walter Roberson]

By "sum" do you mean that you want to know the number of non-zero elements in each row?

Or do you want "sum" to mean according to boolean logic where addition corresponds to "or", and so the result would be 1 if any bit was set and 0 otherwise?

Or do you want "sum" to mean according to xor logic, 0+0 -> 0, 0+1 -> 1, 1+0 -> 1, 1+1 -> 0, and so the result would be 1 if an odd number of bits was set and 0 otherwise?

Answer 1

[Peter Perkins]

There are several ways to do this, here's one particularly simple one. Assuming you are starting with something like this ...

>> tt1 = array2timetable(randi([0 1],5,3),'rowTimes',seconds(1:5))
tt1 =
  5×3 timetable
    Time     Var1    Var2    Var3
    _____    ____    ____    ____
    1 sec     1       1       1  
    2 sec     0       1       0  
    3 sec     1       0       1  
    4 sec     1       0       0  
    5 sec     1       0       1  

... then combine the vars into one, and sum across rows.

>> tt2 = mergevars(tt1,1:3)
tt2 =
  5×1 timetable
    Time        Var1    
    _____    ___________
    1 sec    1    1    1
    2 sec    0    1    0
    3 sec    1    0    1
    4 sec    1    0    0
    5 sec    1    0    1
>> tt2.Var1 = sum(tt2.Var1,2)
tt2 =
  5×1 timetable
    Time     Var1
    _____    ____
    1 sec     3  
    2 sec     1  
    3 sec     2  
    4 sec     1  
    5 sec     2 

Or maybe you want to keep the individual vars around:

    >> tt1.Var4 = sum(tt1{:,:},2)
tt1 =
  5×4 timetable
    Time     Var1    Var2    Var3    Var4
    _____    ____    ____    ____    ____
    1 sec     1       1       1       3  
    2 sec     0       1       0       1  
    3 sec     1       0       1       2  
    4 sec     1       0       0       1  
    5 sec     1       0       1       2  

Answer 2

[Sindar]

% example table
mytable=array2table(randi([0 1],20,10));
% create column variable with sum
sum_all = sum(mytable{:,1:10},2);
% add sum column to table
mytable.sum_all = sum(mytable{:,1:10},2);