topic how to get the variable that is based on cumulative sum of pervious rows and current row? in SAS Programming

how to get the variable that is based on cumulative sum of pervious rows and current row?

ZRick — Sun, 29 Jan 2012 16:42:39 GMT

hi all,

data t;

input m;

cards;

;

data t2;

set t;

k=m+;

output;

run;

I want result like this:

m k

5 5

4 9

11 20

how to get the variable that is based on cumulative sum of pervious rows and current row?

Linlin — Sun, 29 Jan 2012 17:23:17 GMT

data t;

input m;

cards;

;

data want;

set t;

retain k;

k+m;

run;

proc print;run;

Linlin

how to get the variable that is based on cumulative sum of pervious rows and current row?

ZRick — Sun, 29 Jan 2012 18:57:44 GMT

what is the purpose of retain statement?

Is K initially assume as zero?

Should I do following if I want to initial k value other than zero?

data want;

set t;

k=2.4;

retain k;

k+m;

run;

how to get the variable that is based on cumulative sum of pervious rows and current row?

MikeZdeb — Sun, 29 Jan 2012 19:39:29 GMT

hi ... if you don't want to set an initial value, you can skip the RETAIN statement since a SUM statement (K+M) implies retain and starts with an initial value of 0

if you want to set an initial value ... RETAIN K 2.4;

ps http://support.sas.com/documentation/cdl/en/lrdict/64316/HTML/default/viewer.htm#a000289454.htm