How do I accumulate values in a column within in a year (period = months) having multiple years?

[Pili1100]

I have been using the following, which is quite neat when you want to sum values in a column.

IF FIRST.var1 THEN ACC_var1=var1;

ELSE ACC_var+var1;

However, I only have the skills to do it when the dataset only contains 12 months. ^^

How do I accumulate the values within in a year (period = months) when I have multiple years?

For the program code attached I would like to accumulated the 12 months for 2019 and 2020 and the current ones for 2021 for both var1 and var2.

Should I use a DO-loop/some sort of lag solution or is there an another way to use First./ Last.?

I am open for any suggestion. Many thanks!

DATA WORK.temp; 
Infile datalines delimiter=','; 
INPUT YearMonth $ var1 var2 Desired_Accu1 Desired_Accu2
;
CARDS;
2019-01,100,500,100,500
2019-02,200,600,300,1100
2019-03,300,700,600,1800
2019-04,400,100,1000,1900
2019-05,500,200,1500,2100
2019-06,600,300,2100,2400
2019-07,700,400,2800,2800
2019-08,800,500,3600,3300
2019-09,100,500,3700,3800
2019-10,200,600,3900,4400
2019-11,300,700,4200,5100
2019-12,400,100,4600,5200
2020-01,500,200,500,200
2020-02,600,300,1100,500
2020-03,700,400,1800,900
2020-04,800,500,2600,1400
2020-05,100,500,2700,1900
2020-06,200,600,2900,2500
2020-07,300,700,3200,3200
2020-08,400,100,3600,3300
2020-09,500,200,4100,3500
2020-10,600,300,4700,3800
2020-11,700,400,5400,4200
2020-12,800,500,6200,4700
2021-01,100,500,100,500
2021-02,50,300,150,800

;
RUN;

[CarmineVerrell]

You can use the retain statement to accumulate a variable or a sum statement. This topic is discussed in the SAS Programming 2 class in detail. I would recommend you take this course.

Here is an example to your question but only using one of the variables var1 by year.

DATA WORK.temp;
Infile datalines delimiter=',';
INPUT YearMonth $ var1 var2 Desired_Accu1 Desired_Accu2
;
year=substr(yearmonth,1,4);
CARDS;
2019-01,100,500,100,500
2019-02,200,600,300,1100
2019-03,300,700,600,1800
2019-04,400,100,1000,1900
2019-05,500,200,1500,2100
2019-06,600,300,2100,2400
2019-07,700,400,2800,2800
2019-08,800,500,3600,3300
2019-09,100,500,3700,3800
2019-10,200,600,3900,4400
2019-11,300,700,4200,5100
2019-12,400,100,4600,5200
2020-01,500,200,500,200
2020-02,600,300,1100,500
2020-03,700,400,1800,900
2020-04,800,500,2600,1400
2020-05,100,500,2700,1900
2020-06,200,600,2900,2500
2020-07,300,700,3200,3200
2020-08,400,100,3600,3300
2020-09,500,200,4100,3500
2020-10,600,300,4700,3800
2020-11,700,400,5400,4200
2020-12,800,500,6200,4700
2021-01,100,500,100,500
2021-02,50,300,150,800

;
RUN;

proc sort data=WORK.temp;
by Year;
run;

Data work.temp(keep=year var1 ret_var1);
set work.temp;
by year;
if first.year=1 then ret_var1=0;
ret_var1+var1;
run;

[Pili1100 · Accepted solution]

Thank you!

It worked like a charm! 😁

Of course it helps to change to BY Year. If I wasn't completely blocked I should have been able to figure it out. 🤔 

[Reeza]

Create a new variable called YEAR that you can use in your BY statement. You can create it by taking the first four characters of your year month variable.

Now you have a variable you can use with your FIRST and LAST.

DATA WORK.temp; 
Infile datalines delimiter=','; 
INPUT YearMonth $ var1 var2 Desired_Accu1 Desired_Accu2
;
Year = substr(yearMonth, 1, 4);
....

run;

data want;
set temp;
by year;
if first.year then do; 
       accu1 = var1; 
       accu2 = var2;
 end;
else do;
    accu1 = sum(accu1, var1);
   accu2 = sum(accu2, var2);
end;

run;

Or if you can assume you will have complete data, every year/month, you can use the first month as your condition instead, no new variable needed this way. 

if substr(yearMonth, 6, 2) = '01' then .....;

---

@Pili1100 wrote:

I have been using the following, which is quite neat when you want to sum values in a column.

IF FIRST.var1 THEN ACC_var1=var1;

ELSE ACC_var+var1;

However, I only have the skills to do it when the dataset only contains 12 months. ^^

How do I accumulate the values within in a year (period = months) when I have multiple years?

For the program code attached I would like to accumulated the 12 months for 2019 and 2020 and the current ones for 2021 for both var1 and var2.

Should I use a DO-loop/some sort of lag solution or is there an another way to use First./ Last.?

I am open for any suggestion. Many thanks!

DATA WORK.temp; 
Infile datalines delimiter=','; 
INPUT YearMonth $ var1 var2 Desired_Accu1 Desired_Accu2
;
CARDS;
2019-01,100,500,100,500
2019-02,200,600,300,1100
2019-03,300,700,600,1800
2019-04,400,100,1000,1900
2019-05,500,200,1500,2100
2019-06,600,300,2100,2400
2019-07,700,400,2800,2800
2019-08,800,500,3600,3300
2019-09,100,500,3700,3800
2019-10,200,600,3900,4400
2019-11,300,700,4200,5100
2019-12,400,100,4600,5200
2020-01,500,200,500,200
2020-02,600,300,1100,500
2020-03,700,400,1800,900
2020-04,800,500,2600,1400
2020-05,100,500,2700,1900
2020-06,200,600,2900,2500
2020-07,300,700,3200,3200
2020-08,400,100,3600,3300
2020-09,500,200,4100,3500
2020-10,600,300,4700,3800
2020-11,700,400,5400,4200
2020-12,800,500,6200,4700
2021-01,100,500,100,500
2021-02,50,300,150,800

;
RUN;

---