Subtract previous minimum time from current minimum time

[capronton]

I'm using the formula below to calculate "actHdwy". However the formula places the "actHdwy" next to wrong vehicle.
For example, vehicle 5005 does not have "actHdwy" of 11 minutes, bus 5007 should be 11 minutes.
Vehicle 5017 should be 19 minutes, vehicle 5008 should be 11 minutes, 5013 should 16 minutes, etc.,

In other words, how can I modify the formula below to shift the "actHdwy" down to the correct vehicle?
Thanks for any assistance.

WhilePrintingRecords; //Place in Group Footer
if {command.vehicle_id} <> Next({command.vehicle_id}) then
(
Time(next({command.incident_date_time})) -
Time(Minimum ({command.incident_date_time}, {command.vehicle_id}))
)/60
else 0;

incDate sched_time actHdwy vehicle_id
5:10:54 AM 5:07 AM 0 5005
5:13:54 AM 5:07 AM 0 5005
5:15:54 AM 5:07 AM 11 5005

5:21:54 AM 5:22 AM 19 5007

5:40:54 AM 5:37 AM 11 5017

5:51:56 AM 5:52 AM 16 5008

6:07:55 AM 6:07 AM 18 5013

6:25:56 AM 6:22 AM 5 5020

6:30:55 AM 6:34 AM 0 5021
6:40:55 AM 6:34 AM 17 5021

6:47:55 AM 6:49 AM 16 5011

7:03:55 AM 7:04 AM 13 5015

7:16:56 AM 7:16 AM 12 5002

7:28:56 AM 7:28 AM 0 5006
7:30:56 AM 7:28 AM 13 5006

7:41:56 AM 7:40 AM 9 5019

7:50:56 AM 7:52 AM 12 5066

8:02:56 AM 8:04 AM 0 5014
8:04:56 AM 8:04 AM 0 5014
8:06:56 AM 8:04 AM 11 5014

8:13:56 AM 8:16 AM 12 5022

8:25:56 AM 8:28 AM 0 5012
8:26:56 AM 8:28 AM 0 5012
8:27:56 AM 8:28 AM 0 5012
8:31:56 AM 8:28 AM 21 5012

8:46:57 AM 8:42 AM 9 5005

 

[Charliy]

If you want it on the next line, change your logic from using Next to using Previous.

 

[capronton]

I'm trying to subtract previous minimum time from current minimum time, but I get an error.
Can someone explain?

WhilePrintingRecords; //Place in Group Footer
if {command.vehicle_id} <> previous({command.vehicle_id}) then
(
Time(Minimum ({command.incident_date_time}, {command.vehicle_id})) -
Time(previous(Minimum ({command.incident_date_time}, {command.vehicle_id})))
)/60
else 0;

 

[Charliy]

What error do you get?

 

[capronton]

The Error is "This field has no previous value"

(previous(Minimum ({command.incident_date_time}, {command.vehicle_id})))

Is it possible to get the previous minimum incident_date_time?

Or is there another way to subtract previous minimum time from current minimum time?

 

[Charliy]

Add this to the beginning of your formula: Not(onfirstrecord) and .... the rest of your formula.....

 

[capronton]

Just noticed your response Charliy. Thanks.

I think it's going to work the way it is currently set up.