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what's the use of the variable OBS?
Ok, you can try it like the following:
data input;
input x;
datalines;
3
4
7
9
10
20
1
9
11
1
;
run;
data result;
set input;
retain a1-a3;
array e(*) a1-a3;
e(1)=e(2);
e(2)=e(3);
e(3)=x;
min=min(e(1),e(2),e(3));
max=max(e(1),e(2),e(3));
sum=sum(e(1),e(2),e(3));
drop a1-a3;
run;
Gerhard
On Fri, 30 May 2008 04:11:15 -0700, andymanme@GOOGLEMAIL.COM wrote:
>Hi everyone,
>
>I am trying to produce a rolling calculation, every 3 observations
>(but would like the ability to change this).
>
>Given an input dataset I want to look at a rolling observation window
>(of say 3 records) and record against each observation what the
>highest value was in the last 3 observations, the rolling sum and the
>lowest value.
>
>Probably easier to give an example of what I am looking for:
>
>data input;
> input obs x;
>datalines;
>1 3
>2 4
>3 7
>4 9
>5 10
>6 20
>7 1
>8 9
>9 11
>10 1
>;
>run;
>data required;
> input obs x max_3 min_3 sum_3;
>datalines;
>1 3 . . .
>2 4 3 3 3
>3 7 4 3 7
>4 9 7 3 14
>5 10 9 4 20
>6 20 10 7 26
>7 1 20 9 39
>8 9 20 1 31
>9 11 20 1 30
>10 1 11 1 21
>;
>run;
>
>I have tried to put a lag calculation into a DO loop but haven?t been
>able to work out how to go about this.
>
>Help gratefully received!
>Andy
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