Hello everyone,
I'm going to calculate the monthly average of daily temperatures grouping by sensor using retime function. At the moment I'm trying to select each sensor with a loop and then apply the retime function, but I have to calculate six million rows so I would like to avoid a loop to speed up the calculation
I give an example:
Time = datetime({'18-feb-2021';'19-feb-2021';...
'01-mar-2021';'04-mar-2021';'18-feb-2021';...
'19-feb-2021';'01-mar-2021';'04-mar-2021'});
Temp = [56.82;62.72;64.52;63.81;63.45;59.7;60.27;61.32];
Sensor = [12;12;12;12;13;13;13;13];
TT = timetable(Time,Sensor,Temp);
Current code:
uni_sensor = unique(Sensor);
monthly_ds = timetable;
parfor kk = 1:length(uni_sensor)
index_retime = find(TT.Sensor == uni_sensor(kk));
sensor_retime = TT(index_retime,:);
monthly_data = retime(sensor_retime(:,2), 'monthly', 'mean');
data_sensor_retime = array2table(repmat(uni_sensor(kk), size(monthly_data, 1),1), 'VariableNames', "Sensor" );
monthly_sub_id = [monthly_data, data_sensor_retime];
monthly_ds = [monthly_ds; monthly_sub_id];
end
Desired output:
Time = datetime({'feb-2021';'feb-2021';...
'mar-2021';'mar-2021'});
Temp = [59.77;61.575;64.165;60.795];
Sensor = [12;12;13;13];
TT_out = timetable(Time,Sensor,Temp);
Thanks in advance,
Gianluca
