how can i subtract the elements in a coloumn ?

hello

for example, I have : a=[380 0;381 1;382 2;383 3;383 4;383 5;384 6]

I want to go into first column and do this : (381-380), (382-381), (383-382),

how can i do this in a loop or other ways? Thanks for i=1:length(a) b=a(i,1) ????? end

Answer 1

[John D'Errico]

Start reading the tutorials.

diff(a(:,1))

[farfar]

thanks

Answer 2

[Jan]

Do you mean:

diff(a(:,1))

Alternatively with a loop:

n = size(a, 1) - 1;
b = zeros(1, n);
for k = 1:n
   b(k) = a(k+1, 1) - a(k, 1);
end

Or without a loop:

b = a(2:end) - a(1:end - 1);