topic Re: Cumulative count in arrays in SAS Programming

Cumulative count in arrays

Amr_Alaaeldin — Mon, 10 Apr 2017 07:38:29 GMT

the aim of this Question is Counting number of Delinquency during last 12 month But the trick is how to start cumulative count from right to left when find 1 and stop Counting when find 0 Then start counting again when it finds 1

like row number 1 result part .

example :

Data test ;
input A1 A2 A3 A4 A5 A6 A7 A8;
Datalines ;
1 0 1 1 0 1 1 1
1 1 0 0 0 1 1 0
1 1 1 1 1 1 0 0
0 0 0 1 0 1 1 1
1 0 1 1 1 0 0 0
0 1 0 1 0 1 1 1
;
Run ;

The result should be :

B1 B2 B3 B4 B5 B6 B7 B8
1 0 2 1 0 3 2 1
2 1 0 0 0 2 1 0
6 5 4 3 2 1 0 0
0 0 0 1 0 3 2 1
1 0 3 2 1 0 0 0
0 1 0 1 0 3 2 1

Your help is highly appreciated

Re: Cumulative count in arrays

Kurt_Bremser — Mon, 10 Apr 2017 07:50:41 GMT

Declare array for the A and B variables.

Set a counter variable to zero.

In a do loop that counts down from dim(array) to 1, do

- if A(i) is zero, set counter to zero

- if A(i) is 1, add 1 to counter

- set B(i) to counter

Re: Cumulative count in arrays

RW9 — Mon, 10 Apr 2017 08:06:15 GMT

Just to add to @Kurt_Bremser, you don't actually need the counter, just go in reverse from second to end one and then add next cell to the current:

Data test ;
input A1 A2 A3 A4 A5 A6 A7 A8;
Datalines ;
1 0 1 1 0 1 1 1
1 1 0 0 0 1 1 0
1 1 1 1 1 1 0 0
0 0 0 1 0 1 1 1
1 0 1 1 1 0 0 0
0 1 0 1 0 1 1 1
;
Run ;

data want;
  set test;
  array vals{*} a:;
  do i=dim(vals)-1 to 1 by -1;
    if vals{i}=1 then vals{i}=vals{i+1}+1;
  end;
run;

Re: Cumulative count in arrays

Amr_Alaaeldin — Mon, 10 Apr 2017 08:53:18 GMT

Thanks For Quick Reply