How do I use a for loop to read rows of a matrix?

I have 5 excel files with different data, each having a matrix with 2 columns and 3204 rows. The first column is the same for each of the files, but the second column is different. I would like to create a for loop (or any loop that is efficient) to first read 1:801 rows and plot the average, then go through the loop again and average and plot 802:1602, then plot the average a third time of 1603:2403. Any advice?

[Noah Acosta]

all on the same plot

Answer 1

[John]

block_size = 801;

vals = zeros(3,1);

for n = 1:5

data = xlsread(['file', num2str(n), '.xlsx']);

for m = 1:3

vals(m) = mean(data(((m-1)*block_size + 1):m*block_size, 2));

end

end

plot(vals)