topic Re: subsetting dates in Statistical Procedures

subsetting dates

robertrao — Tue, 05 Nov 2013 07:44:36 GMT

Hi,

I have to compare surgery date and lab date

surgery date stays same whereas lab_date changes and the dates are datetimes

we have to check if lab date is +/- 2 weeks from surgery date and keep only those and discard others

Surgery date lab_date

28jun2011:9:30 09jul2011:10:00----------keep

28jun2011:9:30 16jul2011:12:00---------discard(lab date more than 2 weeks from surg date)

28jun2011:9:30 08jul2011:09:00-------keep

Thanks

Re: subsetting dates

Jagadishkatam — Tue, 05 Nov 2013 07:59:24 GMT

please try,

data have;

input date1 : datetime18. date2 : datetime18.;

format date1 date2 datetime18.;

if (datepart(date2)-datepart(date1))/7 >2 then delete;

cards;

28jun2011:9:30 09jul2011:10:00

28jun2011:9:30 16jul2011:12:00

28jun2011:9:30 08jul2011:09:00

;

run;

Thanks,

jagadish

Re: subsetting dates

Iramesh — Wed, 06 Nov 2013 04:56:53 GMT

Hi Jagadish,

But here you're not consider time part.I think you should time part also.

Regards,

Ramesh

Re: subsetting dates

Patrick — Wed, 06 Nov 2013 07:02:16 GMT

I probably would use intck() instead of an expression like "(datepart(date2)-datepart(date1))/7 >2"

SAS(R) 9.2 Language Reference: Dictionary, Fourth Edition

Re: subsetting dates

Jagadishkatam — Wed, 06 Nov 2013 08:44:11 GMT

when i try to use intck function, the result in week is a integer value. so we are unable to check if the week is 2 or more than 2. as per the data provided the second record is more than 2 weeks, however with intck it is 2.

data have;

input date1 : datetime18. date2 : datetime18.;

format date1 date2 datetime18.;

value1=(datepart(date2)-datepart(date1))/7;

value=intck('week', datepart(date1), datepart(date2));

cards;

28jun2011:9:30 09jul2011:10:00

28jun2011:9:30 16jul2011:12:00

28jun2011:9:30 08jul2011:09:00

;

run;

Please check the difference between value1 and value variables. is there any way to avoid it with intck. please suggest.

Re: subsetting dates

Patrick — Wed, 06 Nov 2013 21:04:09 GMT

With datetime values I would use the datetime intervals with intck().

if intck('dtday', date1, date2) > 13 then delete;

Re: subsetting dates

Jagadishkatam — Thu, 07 Nov 2013 01:57:42 GMT

Thanks Patrick , indeed a good way