How do I substract like variables from each other

I have a table that looks like Book1_1, I need help with figuring out if Var1 row 1 ==Var1 row 2 then subtract Var2 row 2 from Var2 row 1 and continue down till the end of the table (this subtract answer would then create a new variable but I do not need help with creating a new variable just how to subtract likes from likes). Thank you.

[Torsten]

Show us the expected result for Book1_1.

[Elysia]

[Zahrah Walid]

I guess this is somehow similar to your problem: https://www.mathworks.com/matlabcentral/answers/18717-time-difference-between-two-sets-of-times-in-hrs-mins-and-seconds-gui-if-possible

Answer 1

[Arif Hoq]

one approach:

a=readmatrix("Book1.xlsx");
b= datetime(a,'ConvertFrom','excel');
% b(:,3)=b(:,2);
for i=1:size(b,1)-1
    if b(i,1)==b(i+1,1)
        c(i)=b(i+1,2)-b(i,2);
    end
end
output=c'

output = 5×1 duration array
   00:05:00
   00:04:49
   00:10:10
   00:00:00
   00:02:19

Answer 2

[Voss]

a = readmatrix("Book1.xlsx");
b = datetime(a(:,2),'ConvertFrom','excel');
N = size(a,1);
c = duration(NaN(N,3));
for i = 1:N-1
    if a(i,1) == a(i+1,1)
        c(i+1) = b(i+1)-b(i);
    end
end

disp(c);

        NaN
   00:05:00
   00:04:49
   00:10:10
        NaN
   00:02:19