need to find difference of two cells from one column in Excel

Hi, I have an excel where column one(Time) has some values and column 5 (Duration), in duration i need to find the difference of 2nd element - 1st element from column one, i dont want to hard code that on excel, i want write that piece of code in .m file, how do i do it?

[num2, text, alldata2]=xlsread('exp2.xlsx');

temptime=num2(:,1); % getting column one from excel

holder=length(temptime); % getting to know how many elements are there in column one

i=1;

for i = 1:holder

     duration()=(temptime(i)-temptime(i-1)); %its failing here

 end

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Answer 1

[ahmed nebli]

i think it should be done this way:

for i = 2:holder % the counter must get from 2 because temptime(i-1) would be error duration()=(temptime(i)-temptime(i-1)); %its failing here end

[raghavendra kandukuri]

Thank you, Ahmed.