How to find difference between two Excel data series with differing timestamps on X-axis?

3
votes

How can I find the value difference between two data series on an Excel scatter graph, when both of the series have different timestamp entries for the X-axis? For example:

Series 1
11:20:02    333
11:20:15    332
11:20:28    325

Series 2
11:20:04    992
11:20:11    944
11:20:18    932

Therefore I need to find the difference between the lines which have been plotted rather than the actual data-points... Is this even possible in Excel?

1
excel

1 Answers

1
votes

You could interpolate from your larger x range (Series 1) using FORECAST. Basically, the FORECAST function works as such:

=FORECAST(x value you want, known y values, known x values)

For example, you would fill a cell in with:

=FORECAST(11:20:04, B2:B3, A2:A3)

Where I'm assuming your sample data is in columns A and B. This would give you some y value at 11:20:04 for your series 1 that you could subtract from the value at 11:20:04 from series 2 to make a third graph. I hope this helps!