How to calculate 8 days mean from ten years data?
I have a code which calculates the 8days mean from single year. It computes 45 eight days from 45X8 = 360 days and last 8days mean from remaining 5 or 6 days of the year. I wish to use this code over ten years data with the same method as mentioned in previous line. It should not jump to next year to complete last 8 days. It should start from the 1st January and finish at 31 December of each year and then keep on doing similar way so till the end of all the data. I request you all to kindly suggest me some checks in this code to run this code over a length of continuous ten years data without overlapping between years. The code is as follows: data_matrix=readmatrix('c:/data/test.csv'); start = 1:8:height(data_matrix); stop = unique([start(2:end)-1, height(data_matrix)]); nbins = numel(stop); dataAverages = nan(nbins, width(data_matrix)); for i = 1:nbins rows = start(i) : stop(i); dataAverages(i,:) = mean(data_matrix(rows, :), 1, 'omitnan'); end disp(dataAverages) size(dataAverages) % Write output as matrix in csv format filename = 'c:/data/test_out.csv' writematrix(dataAverages,filename);
Kshitij Singh answered .
2025-11-20
%% read data file
[lines, ~] = readlog('Test2.csv'); % fex : https://fr.mathworks.com/matlabcentral/fileexchange/96364-readlog?s_tid=srchtitle
data_matrix = split(lines,',');
[m,n] = size(data_matrix);
ind_start_year = find(startsWith(data_matrix(:,1),'1-Jan-')); % find row corresponding to first day of the year
ind_stop_year = find(startsWith(data_matrix(:,1),'31-Dec-')); % find row corresponding to last day of the year
toc
%% main loop
windowSize = 8; % define buffer length for averaging
cols = 3:n; % define cols to be processed
dataAverages_total = [];
% if the data file stops before a 31 Dec , we must add this :
if numel(ind_stop_year) < numel(ind_start_year)
ind_stop_year = [ind_stop_year; m];
end
for ck = 1:numel(ind_start_year)% loop over year number
ind_start_thisyear = ind_start_year(ck);
ind_stop_thisyear = ind_stop_year(ck);
start = ind_start_thisyear:windowSize:ind_stop_thisyear;
stop = [start(2:end)-1, ind_stop_thisyear];
dur = stop-start+1;
nbins = numel(start);
dataAverages = nan(nbins, numel(cols));
for ci = 1:nbins
rows = start(ci) : stop(ci);
tmp = data_matrix(rows, :);
dataAverages(ci,:) = mean(str2double(tmp(:,3:n)), 1, 'omitnan'); % results of one year
end
sum(dur)
dataAverages_total = [dataAverages_total ; dataAverages]; % concatenate every year's result (dataAverages)
end