Using info from previous summary

[sgonzo]

I have information as Event, EventTimeGroup, SecondCount.

I am able to summary the beginning and ending SecondCount for each EventTimeGroup.

However, I want to know the difference between the ending SecondCount of the previous EventTimeGroup and the beginning SecondCount of the current EventTimeGroup.

Example: Thing1 1 22

thing2 1 44

thing3 1 66

thing4 2 88

thing5 2 99

I know that EventTimeGroup 1 began at 22 and ended at 66, and that EventTimeGroup 2 began at 88 and ended at 99. (Using summaries based on sorting by EventTimeGroup.)

How can I calculate that 22 second elapsed since EventTimeGroup 1 ended and EventTimeGroup 2 began?

Thank you in advance for any help.

[transpower]

You could add a Previous_EventTimeGroup field to the table. Then create another TO (Table Occurrence) and create a link between the first table and the TO, with the link being between the Previous_EventTimeGroup and EventTimeGroup (and record R related to record R-1). Then do a simple subtraction in the first table to get the elapsed time.

[sgonzo]

Thanks. It's great that you experts are so patient with us novices.

This forum has given me insight into how to think about Filemaker. Of all the programs I've used, this one has taken the longest to get a grasp on the logic, as data and design are meshed. Sort wrong and you've got the wrong answers.