Calculate minutes average values

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Ann
Ann 2021-1-5
评论： Ann 2021-1-6
Hi, everyone.
As attached is my observations data for 24 hours from different transmitter (PRN) . The data here are from 1/1/2014 to 31/1/2014 resulting in thousands of row. From this excel (refer attachment), I need to extract 1-minute and 5-min averages for VTEC, S4 and Sigma for each 31 days.
Therefore, later I can do plotting for the graph but currently stuck here finding shortcut to find averages with thousands of data. Does anyone have any ideas? Thank you in advanced.
From Excel:
Column A - Day Column B- Time Column C- GPS TOW (may ignore)
Column D- PRN
Column E- VTEC Column F- S4 Column G- Sigma

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Cris LaPierre
Cris LaPierre 2021-1-5
Ran in:
I would import the spreadsheet as a table, then convert the day and time into a datetime, convert that to a timetable, and use the retime function to combine the data into 1 minute and 5 minute increments.
data = readtable("Book_Jan.xlsx");
Warning: Column headers from the file were modified to make them valid MATLAB identifiers before creating variable names for the table. The original column headers are saved in the VariableDescriptions property.
Set 'VariableNamingRule' to 'preserve' to use the original column headers as table variable names.
% Convert DAY and TIME into durations
data.DAY = days(data.DAY);
data.TIME = days(data.TIME);
% Create a datetime
data.TimeStamp = datetime(2014,01,01) + data.DAY-1 + data.TIME;
data.TimeStamp.Format = "MM-dd-yy HH:mm";
% Convert the table to a timetable
dataTT = table2timetable(data,"RowTimes","TimeStamp");
% Use retime to average the data into 1 and 5 minute increments.
dataTT1min = retime(dataTT(:,["VTEC" "S4" "Sigma"]),"minutely","mean")
dataTT1min = 44636x3 timetable
TimeStamp VTEC S4 Sigma ______________ ______ ________ ________ 01-01-14 00:04 9.4936 0.051653 0.037328 01-01-14 00:05 15.034 0.053267 0.044752 01-01-14 00:06 10.191 0.0471 0.037384 01-01-14 00:07 12.139 0.071698 0.045127 01-01-14 00:08 NaN NaN NaN 01-01-14 00:09 15.691 0.054704 0.043895 01-01-14 00:10 3.8546 0.039522 0.035422 01-01-14 00:11 13.002 0.068763 0.040811 01-01-14 00:12 15.675 0.090359 0.045485 01-01-14 00:13 NaN NaN NaN 01-01-14 00:14 10.517 0.044855 0.038009 01-01-14 00:15 12.454 0.053156 0.03739 01-01-14 00:16 10.704 0.052649 0.036479 01-01-14 00:17 2.0486 0.05072 0.049246 01-01-14 00:18 8.1786 0.041343 0.036154 01-01-14 00:19 NaN NaN NaN
dataTT5min = retime(dataTT(:,["VTEC" "S4" "Sigma"]),"regular","mean","TimeStep",minutes(5))
dataTT5min = 8928x3 timetable
TimeStamp VTEC S4 Sigma ______________ ______ ________ ________ 01-01-14 00:00 9.4936 0.051653 0.037328 01-01-14 00:05 12.902 0.058996 0.042836 01-01-14 00:10 11.94 0.065468 0.04091 01-01-14 00:15 9.2135 0.04967 0.038829 01-01-14 00:20 6.063 0.046863 0.036622 01-01-14 00:25 8.6923 0.084346 0.038214 01-01-14 00:30 14.037 0.067668 0.036141 01-01-14 00:35 15.687 0.069287 0.044902 01-01-14 00:40 16.367 0.06382 0.04569 01-01-14 00:45 14.388 0.046352 0.037041 01-01-14 00:50 16.051 0.050894 0.031428 01-01-14 00:55 15.175 0.048557 0.032849 01-01-14 01:00 19.772 0.066493 0.03821 01-01-14 01:05 17.465 0.076747 0.045897 01-01-14 01:10 19.234 0.062305 0.039331 01-01-14 01:15 17.724 0.055996 0.039595
  1 个评论
Ann
Ann 2021-1-6
Thank you, sir!
It works like a charm and I really appreciate that!

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