How to read data in excel file and make if statement to build another column

Hello, I am trying to do some post processing in MATLAB

Let's say there is a excel file contains information like below

time x y z

1 x1 y1 z1

2 x2 y2 z2

3 x3 y3 z3

4 x4 y4 z4

..........

What I am trying to do is read the information in specific location, and make a if statement to build another column. For example, I want to find y that has value between 1 and 2, and from that point make another column starting from that row containing y value satisfies the condition and save it. What shall I do?

time x y z a

1 x1 y1 z1 a1

2 x2 y2 z2 a2

3 x3 y3 z3 a3

4 x4 y4 z4 a4 ..........

Answer 1

[Guillaume]

What you should do is not use an if statement and rather use the proper functions. It's not exactly clear what the final aim. This should get you started

%load excel file using readtable (a lot more powerful than xlsread)
data = readtable('c:\\somewhere\somefile.xlsx');  %should result in a table with columns time, x, y, z
%locate rows where y is between 1 and 2
isinrange = data.y >= 1 & data.y <= 2;  %no if needed! isinrange is a logical array
%not sure what you want to do from here, let's create a new column that is x+y when y is in range:
data.a = zeros(height(data), 1);  %create new column full of 0s
data.a(isinrange) = data.x(isinrange) + data.y(isinrange)
%or let's fill column a with value from the 1st row where y is in range:
data.a = zeros(height(data), 1); %create new column (or reset it)
startrow = find(isinrange, 1);  %find index of first row that is in range
data.a(startrow:end) = 1 : height(data)-startrow+1

[young jin Kwak]

Thank you so much, you have been great help.