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creating a look up table to compare datetime stamps

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I need to create a look up table, where i would need to specify. This will need to a manual table, where i would need to spicify the following:
Start DateTimeStamp, Stop DateTimeStamp and Device ID.
Then i would like to compare a incoming datastreams timestamp, aganist this lookup table to to NaN samples between the dates.
How can i create a table from Matlab, instead of using spreadsheet and how do you compare timestamps?

Accepted Answer

Star Strider
Star Strider on 20 Nov 2022
Start with the isbetween function, and add a separate logical vector for the device ID —
DateTime = datetime('now')+hours(0:4:150).';
DeviceID = randi(9, size(DateTime));
T1 = table(DateTime,DeviceID)
T1 = 38×2 table
DateTime DeviceID ____________________ ________ 20-Nov-2022 16:09:11 6 20-Nov-2022 20:09:11 3 21-Nov-2022 00:09:11 4 21-Nov-2022 04:09:11 8 21-Nov-2022 08:09:11 1 21-Nov-2022 12:09:11 4 21-Nov-2022 16:09:11 2 21-Nov-2022 20:09:11 8 22-Nov-2022 00:09:11 7 22-Nov-2022 04:09:11 7 22-Nov-2022 08:09:11 4 22-Nov-2022 12:09:11 5 22-Nov-2022 16:09:11 5 22-Nov-2022 20:09:11 5 23-Nov-2022 00:09:11 4 23-Nov-2022 04:09:11 8
Start_DateTimeStamp = "21-Nov-2022 12:00";
Stop_DateTimeStamp = "22-Nov-2022 18:00";
Device_ID = randi(9)
Device_ID = 7
Lv = isbetween(T1.DateTime, Start_DateTimeStamp, Stop_DateTimeStamp) & Device_ID==T1.DeviceID;
Query = nnz(Lv)
Query = 2
Result = T1(Lv,:)
Result = 2×2 table
DateTime DeviceID ____________________ ________ 22-Nov-2022 00:09:11 7 22-Nov-2022 04:09:11 7
Make appropriate changes to work with your data.
dpb on 23 Nov 2022
Nothing prevents you from organizing the file structure however it best suits the task...
Again, you've given us absolutely no context with which to work; how are we to have any idea of any specific organization or code structure that would fit?
Dharmesh Joshi
Dharmesh Joshi on 24 Nov 2022
Well i have sensors, such as tempeture,Humdity, motion etc , that are reporting data to our cloud servers as JSON. Then using API i am downloading that data onto Matlab.
But these sensors if they are placed away from the site, will produce false results, so the aim is to specify the timestamps and make the data NaN to avoid any confussion.

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More Answers (1)

dpb on 20 Nov 2022
Read all about <MATLAB timetable> here. It has all the tools ready-built for you...


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