topic Random Number generator to impute month and day as part of date question in SAS Programming

Random Number generator to impute month and day as part of date question

statadm — Tue, 23 Mar 2010 17:58:03 GMT

I have a program to impute either a missing day or month and day using ranuni.

The problem is that the random date sometimes falls into a range that is impossible, ie. less than a start date.

Does anyone know of a way to restrict this randomization so that the imputed day/month is not less than the day/month of the start date if they fall within the same month/year ?

Thanks in advance !

Re: Random Number generator to impute month and day as part of date question

sbb — Tue, 23 Mar 2010 18:19:14 GMT

You can use the INTNX function to set a low/high start/stop range within your code.

DATA _NULL_;
FORMAT LOWDATE HIDATE DATE9.;
LOWDATE = INTNX('MONTH',TODAY(),-12,'SAMEDAY');
HIDATE = INTNX('MONTH',TODAY(),12,'SAMEDAY');
PUTLOG _ALL_;
RUN;

Scott Barry
SBBWorks, Inc.

Useful SAS support website reference on this topic:

http://support.sas.com/techsup/technote/ts668.pdf

Re: Random Number generator to impute month and day as part of date question

Patrick — Wed, 24 Mar 2010 13:31:55 GMT

I believe the code below does what you're looking for:

data _null_;
format StartDate RandomDate date9.;
StartDate=today();
DateRange=60;
do i=1 to 20;
/* RandomDate within range StartDate to Startdate+59 days */
RandomDate=Startdate+floor(ranuni(0)*DateRange);
put RandomDate=;
end;
run;

If you need to calculate the date range more dynamically then look at Scott's code.

HTH
Patrick