topic Resetting Lag Fields in SAS Programming

Resetting Lag Fields

cbrotz — Thu, 06 Jul 2017 19:46:56 GMT

Is there a way to reset Lag fields to 0? I have the following code and want to reset the values in x1-11 when I move to a new by group based on level 1 and level 2. I tried resetting in a do loop but that is not working.....thanks for the help!

DATA ADD_LAGS;
SET WORK.SUMMARY_RET_DATA;
BY level1 level2 YYYYMM SUM_OF_BILLINGS;
*retain x1-x11 Rolling_12;
if first.level1 then do;
                              x1=0;
                              x2=0;
                              x3=0;
                              x4=0;
                              x5=0;
                              x6=0;
                              x7=0;
                              x8=0;
                              x9=0;
                              x10=0;
                              x11=0;
                           end;

x1 =lag1(sum_of_Billings);
x2 =lag2(sum_of_Billings);
x3 =lag3(sum_of_Billings);
x4 =lag4(sum_of_Billings);
x5 =lag5(sum_of_Billings);
x6 =lag6(sum_of_Billings);
x7 =lag7(sum_of_Billings);
x8 =lag8(sum_of_Billings);
x9 =lag9(sum_of_Billings);
x10=lag10(sum_of_Billings);
x11=lag11(sum_of_Billings);

If _N_ = 1 then Rolling_12 = sum_of_Billings;
   Else if _N_ < 12 then Rolling_12 + sum_of_Billings;
   Else Rolling_12 = sum(sum_of_Billings,x1,x2,x3,x4,x5,x6,x7,x8,x9,x10,x11);


run;

Re: Resetting Lag Fields

Tom — Thu, 06 Jul 2017 20:23:19 GMT

You could first calculate the lagged values then reset the ones that don't apply.

DATA ADD_LAGS;
  SET WORK.SUMMARY_RET_DATA;
  BY level1  level2  YYYYMM SUM_OF_BILLINGS;

x1 =lag1(sum_of_Billings);
x2 =lag2(sum_of_Billings);
x3 =lag3(sum_of_Billings);
x4 =lag4(sum_of_Billings);
x5 =lag5(sum_of_Billings);
x6 =lag6(sum_of_Billings);
x7 =lag7(sum_of_Billings);
x8 =lag8(sum_of_Billings);
x9 =lag9(sum_of_Billings);
x10=lag10(sum_of_Billings);
x11=lag11(sum_of_Billings);
    array x x1-x11 ;
    n+1;
    if first.level1 then n=1;
    do i=n to dim(x) ;
       x(i)=0;
    end;
   ...

Re: Resetting Lag Fields

Kurt_Bremser — Fri, 07 Jul 2017 07:29:48 GMT

Follow @Tom's suggestion.

Don't post example data as Excel files. Excel spreadsheets do not convey important information about the dataset structure (variable types, lengths, formats), and are blocked at many corporate sites for security reasons.

Use the macro provided in https://communities.sas.com/t5/SAS-Communities-Library/How-to-create-a-data-step-version-of-your-data-AKA-generate/ta-p/258712 to convert your dataset to a datastep that can be posted in a code window (buttons ##6 and #7 on top of the posting window) and allows recreation of your dataset by a simple copy/paste and run.