topic Re: Sum variable by relative dates in SAS Programming

Sum variable by relative dates

Walternate — Tue, 14 Jul 2015 20:15:26 GMT

Hi,

I have two datasets. Dataset 1 is at the person level and has ID, a date variable, and a series of variables named for year/month combinations. A value of 0 for a year/month variable means that the person was absent in that year/month; a value of 1 means that they were present:

ID Date1 Jan2010 Feb2010....etc through Mar2015

1 1/4/12 0 1 0

2 5/9/12 1 0 0

3 4/12/13 1 1 1

Dataset 2 is at the person/date level; that is, each row is one person on one date. Each row also has a number associated with it (number of events):

ID Date2 Num_events

1 2/3/2014 5

1 10/12/2014 1

1 11/5/2014 2

2 1/1/2012 2

2 5/7/2013 3

I have joined the datasets on ID, and I need two different things:

1. I need every person's total num_events by month/year combo--however, this needs to be cross-referenced with the year/month variables, because if they have a value of 1 for that year/month but no events, they should have a value of 0 rather than missing.

For example, ID 1 was present in Feb 2010 because they have Feb2010=1. In Dataset 2, they have no events in Feb 2010 (because they have no record for Feb 2010). Therefore, ID 1's total events for Feb 2010 should=0. However, they were absent in Jan 2010 (Jan2010 var=0), so their event total for Jan 2010 will be null, not 0.

2. Even more complicated--ultimately what I want is to have everyone's event total relative to their own Date1 (the date variable in Dataset 1). That is, the event total for ID 1 in Dec 2011 would be -1 month from their Date1 var, but for ID 2 it would be -5 months from their Date1 var.

Basically, I can't figure out how to reconcile all of these elements. I was able to create a dataset of total events by relative month by calculating a new variable which counted the number of months between Date1 and Date2 (mth_diff), then doing

proc sql;

create table mthly_sums as

select ID, mth_diff, sum(num_events) as tot

from have

group by ID, mth_diff;

quit;

But that doesn't incorporate the mth/year vars and the fact that people who were present but had no events should be 0 and not missing.

Re: Sum variable by relative dates

ChrisNZ — Wed, 15 Jul 2015 11:15:42 GMT

Give us a small set of data to play with:

data set have1

data set have2

data set want

Re: Sum variable by relative dates

Patrick — Wed, 15 Jul 2015 11:37:29 GMT

To give you an answer here I have to try and test and I don't want to do all the work. So please provide proper data steps creating sample data and then show us how the desired result needs to look like.

Re: Sum variable by relative dates

Walternate — Wed, 15 Jul 2015 12:51:38 GMT

Here is the code to create Dataset1 (I used just one year of data):

data dataset1;

input id date1 mmddyy10. present_201001 present_201002 present201003 present201004 present201005 present201006

present_201007 present_201008 present201009 present201010 present201011 present201012;

format date1 mmddyy10.;

cards ;

1 01/07/2010 1 1 1 1 1 1 1 1 1 1 1 1

2 05/09/2010 0 0 0 0 1 1 1 1 1 1 1 1

3 04/12/2010 1 1 1 1 1 1 1 1 1 1 1 1

4 03/19/2010 1 1 1 1 1 1 1 1 1 0 0 0

5 12/07/2010 1 1 1 1 1 1 1 1 1 1 1 1

;

run;

This is the output dataset when you run that code:

id	date1	present_201001	present_201002	present_201003	present_201004	present_201005	present_201006	present_201007	present_201008	present_201009	present_201010	present_201011	present_201012
1	1/7/2010	1	1	1	1	1	1	1	1	1	1	1	1
2	5/9/2010	0	0	0	0	1	1	1	1	1	1	1	1
3	4/12/2010	1	1	1	1	1	1	1	1	1	1	1	1
4	3/19/2010	1	1	1	1	1	1	1	1	1	0	0	0
5	12/7/2010	1	1	1	1	1	1	1	1	1	1	1	1

Here is the code for Dataset2:

data dataset2;

input id date2 mmddyy10. event_num;

format date2 mmddyy10.;

cards ;

1 1/9/2010 17

1 1/21/2010 23

1 2/4/2010 32

1 2/7/2010 12

1 4/5/2010 14

1 4/10/2010 1

1 4/21/2010 9

1 5/4/2010 91

1 5/9/2010 17

1 6/12/2010 33

2 5/4/2010 56

2 5/12/2010 74

2 5/30/2010 80

2 6/4/2010 11

2 6/20/2010 52

2 10/12/2010 63

2 10/29/2010 78

2 10/31/2010 33

3 1/24/2010 12

3 1/27/2010 10

3 2/3/2010 8

3 2/7/2010 9

3 2/17/2010 19

3 7/9/2010 22

3 7/14/2010 55

4 1/23/2010 29

4 1/27/2010 44

4 1/29/2010 35

4 3/5/2010 74

4 3/14/2010 92

4 7/2/2010 2

4 7/5/2010 13

4 8/9/2010 53

5 1/5/2010 72

5 1/23/2010 49

5 1/24/2010 14

5 9/5/2010 20

5 9/7/2010 11

5 9/12/2010 1

5 12/1/2010 4

5 12/31/2010 14

;

run;

The output dataset:

id	date2	event_num
1	1/9/2010	7
1	1/21/2010	23
1	2/4/2010	2
1	2/7/2010	2
1	4/5/2010	4
1	4/10/2010	1
1	4/21/2010	9
1	5/4/2010	1
1	5/9/2010	7
1	6/12/2010	33
2	5/4/2010	6
2	5/12/2010	74
2	5/30/2010	80
2	6/4/2010	1
2	6/20/2010	52
2	10/12/2010	63
2	10/29/2010	78
2	10/31/2010	33
3	1/24/2010	12
3	1/27/2010	10
3	2/3/2010	3
3	2/17/2010	19
3	7/9/2010	2
3	7/14/2010	55
4	1/23/2010	29
4	1/27/2010	44
4	1/29/2010	35
4	3/5/2010	4
4	3/14/2010	92
4	7/2/2010	4
4	8/9/2010	3
5	1/5/2010	2
5	1/23/2010	49
5	1/24/2010	14
5	9/5/2010	0
5	9/7/2010	11
5	9/12/2010	1
5	12/1/2010	4
5	12/31/2010	14

The format of the dataset I want doesn't matter--the sums could be in columns or in rows, but the basic idea is:

1. Sums of event_num in each month relative to each person's date 1 (ie, -1 month, etc)

2. If a person does not have any events in a given month, they should have a missing value for the sum variable for that month UNLESS the present_201001 etc. vars from Dataset1 indicate that they were present in that month (=1), in which case, they should have a value of 0.

So one possible final dataset would be like this:

ID	Pre_date1_12_mths	Pre_date1_11_mths	Pre_date1_10_mths	Pre_date1_9_mths	Pre_date1_8_mths	Pre_date1_7_mths	Pre_date1_6_mths	Pre_date1_5_mths	Pre_date1_4_mths	Pre_date1_3_mths	Pre_date1_2_mths	Pre_date1_1_mths	Same_mth_as_Date1	Post_date1_1_mths	Post_date1_2_mths	Post_date1_3_mths	Post_date1_4_mths	Post_date1_5_mths	Post_date1_6_mths	Post_date1_7_mths	Post_date1_8_mths	Post_date1_9_mths	Post_date1_10_mths	Post_date1_11_mths	Post_date1_12_mths
1	.	.	.	.	.	.	.	.	.	.	.	.	30	4	0	14	8	33	0	0	0	0	0	0	.
2	.	.	.	.	.	.	.	.	.	.	.	.	160	53	0	0	0	174	0	0	.	.	.	.	.
3	.	.	.	.	.	.	.	.	.	22	22	0	0	0	0	57	0	0	0	0	0	.	.	.	.
4	.	.	.	.	.	.	.	.	.	.	108	0	96	0	0	0	4	3	0	.	.	.	.	.	.
5	65	0	0	0	0	0	0	0	0	12	0	0	18	.	.	.	.	.	.	.	.	.	.	.	.

But it could also be the same numbers structured in a different way, like this:

ID Relative_mth total

1 -12 .

etc.

Re: Sum variable by relative dates

ChrisNZ — Wed, 15 Jul 2015 23:44:29 GMT

This gives the values you are after.

data T1;
input ID DATE1 mmddyy10.

PRESENT_201001 PRESENT_201002 PRESENT201003 PRESENT201004 PRESENT201005 PRESENT201006
PRESENT_201007 PRESENT_201008 PRESENT201009 PRESENT201010 PRESENT201011 PRESENT201012;
DATE1=intnx('month',DATE1,0);
format DATE1 monyy.;
cards ;
1 01/07/2010 1 1 1 1 1 1 1 1 1 1 1 1
2 05/09/2010 0 0 0 0 1 1 1 1 1 1 1 1
3 04/12/2010 1 1 1 1 1 1 1 1 1 1 1 1
4 03/19/2010 1 1 1 1 1 1 1 1 1 0 0 0
5 12/07/2010 1 1 1 1 1 1 1 1 1 1 1 1
run;

data T1A (keep=ID DATE1 DATE2 PRESENT); %* Prepare data for merge;

   set T1;
   array DATES [12] PRESENT:;
   do I=1to12;
     DATE2=intnx('month','01jan2010'd,I-1);
     PRESENT=DATES;
     output;
   end;
   format DATE2 monyy.;
run;

data T2;
input ID    DATE2 : mmddyy.     EVENT_NUM ;
DATE2=intnx('month',DATE2,0);
format DATE2 monyy.;
cards;
1      1/9/2010      7
1      1/21/2010     23
1      2/4/2010      2
1      2/7/2010      2
1      4/5/2010      4
1      4/10/2010     1
1      4/21/2010     9
1      5/4/2010      1
1      5/9/2010      7
1      6/12/2010     33
2      5/4/2010      6
2      5/12/2010     74
2      5/30/2010     80
2      6/4/2010      1
2      6/20/2010     52
2      10/12/2010    63
2      10/29/2010    78
2      10/31/2010    33
3      1/24/2010     12
3      1/27/2010     10
3      2/3/2010      3
3      2/17/2010     19
3      7/9/2010      2
3      7/14/2010     55
4      1/23/2010     29
4      1/27/2010     44
4      1/29/2010     35
4      3/5/2010      4
4      3/14/2010     92
4      7/2/2010      4
4      8/9/2010      3
5      1/5/2010      2
5      1/23/2010     49
5      1/24/2010     14
5      9/5/2010      0
5      9/7/2010      11
5      9/12/2010     1
5      12/1/2010     4
5      12/31/2010    14
run;
proc summarydata=T2 nway; %* Prepare data for merge;
class ID DATE2;
var EVENT_NUM;
outputout=T2A(keep=ID DATE2 EVENT_NUM) sum=;
run;

data T3; %* Merge;

merge T1A T2A;
by ID DATE2;
TOTAL= ifn(PRESENT=1, max(0, EVENT_NUM ), .) ;
run;