topic Re: Forming time groups in SAS Programming

Forming time groups

RandyStan — Tue, 04 Oct 2022 03:36:22 GMT

Dear All:

Here is the code I wrote:

Data want ; set have;

if Year < 2015 then VarA = INTCK ('Minute25.' , '10:00:00't , time); else

if year >= 2015 then VarA = INTCK ('Minute25.' , '09:15:00't, time) ;

run;

I cannot get the 25 minute intervals starting at different times for the different years. What mistake am I making?

Randy

Re: Forming time groups

MarkusWeick — Tue, 04 Oct 2022 05:40:22 GMT

Hi @RandyStan,

does it work for the years < 2015?

Best

Markus

Re: Forming time groups

Kurt_Bremser — Tue, 04 Oct 2022 05:43:45 GMT

Maxim 2.

Please post the complete log of your step.

Re: Forming time groups

FreelanceReinh — Tue, 04 Oct 2022 11:11:07 GMT

Hello @RandyStan,

I think for year >= 2015 you want to count 25-minute intervals starting at '09:15:00't, i.e., the first interval ends at '09:39:59't. For this you need to request the continuous method in the fourth argument of the INTCK function:

if year >= 2015 then VarA = INTCK ('Minute25', '09:15:00't, time, 'c');

With the default discrete method the first interval boundary after '09:15:00't is between '09:34:59't and '09:35:00't = 23*'0:25:00't (integer multiple of the interval starting at '0:00:00't). You don't have this problem for the other years because '10:00:00't (unlike '09:15:00't) happens to be an integer multiple of '0:25:00't: '10:00:00't = 24*'0:25:00't. So in that case the discrete and the continuous method yield the same results. For consistency and clarity you could specify the 'c' argument in both cases.

Edit:

Example: The number of 25-minute intervals from 9:15 through 10:28 is ...

3 = intck('minute25','09:15't,'10:28't) by the discrete method (counting the 0:00-based interval boundaries at 9:35, 10:00 and 10:25)
2 = intck('minute25','09:15't,'10:28't,'c') by the continuous method (counting the 9:15-based interval boundaries at 9:40 and 10:05)
2.92 = ('10:28't-'09:15't)/'0:25't by measuring the time difference in units of 25 minutes rather than counting interval boundaries.

Re: Forming time groups

RandyStan — Wed, 05 Oct 2022 16:21:08 GMT

Thanks much