Calculations with time stamped data

[bacon4life]

I have several set of data that are timestamped that I would like to correlate and do math on. Any good ways to this in excel? Or some other program?. An example would be calculating V*A on half hour intervals given the following data:

voltage 1:00 120
voltage 2:00 121
voltage 3:00 121
voltage 4:00 119
voltage 5:00 119
Amps 12:45 50
Amps 1:10 50
Amps 2:15 79
Amps 2:25 80
Amps 2:45 81
Amps 3:20 80
Amps 4:25 70
Amps 5:30 60

The interpolation doesn't need to be real accurate as I would like to use this to look for trends/outliers to investigate more carefully.

 

[IRstuff]

Not sure what you mean. Time is stored as serial numbers where days are whole numbers and hours are 1/24 of a day. You can simply reformat the time column as normal numbers to show the serial numbers.

TTFN

FAQ731-376

 

[melone]

So let me get this straight.... You measured the voltage at 1:00, and the current at 1:10, and you want the V*A for 1:00 and 1:30?

 

[IRstuff]

Oh, sorry for misreading. You can do a brute-force linear interpolation.

TTFN

FAQ731-376

 

[bacon4life]

Yes melone, I know it sounds kind of strange. However assuming the data is approximately linear, interpolation should be enough to identify trends.

I have filled in example results to the data table. I am looking at data from a couple of different data historians. One of them records every 1 hour, one of them records the Highest and lowest in every 1 hour period, and 1 captures a data point every time the value changes significantly.


Type of time value time Formula VA
measure
voltage 1:00 PM 120 1:00 =120.00*50.0 6000
voltage 2:00 PM 121 1:15 =120.25*50.0 6013
voltage 3:00 PM 121 1:30 =120.50*57.5 6929
Amps 12:45PM 50 1:45 =120.75*65.0 7849
Amps 1:15 PM 50 2:00 =121.00*72.5 8773
Amps 2:15 AM 80 2:15 =121.00*80.00 9680
Amps 2:30 AM 90 2:30 =121.00*90.00 10890