Calculating cumulative sum

[ilikesas]

Hi,

my question might be too simple but I actually have some trouble figuring it out...

what I want to do is to calculate the cumulative sum of a column, so if I have the following table:

value
10
20
30
40

I would like to add to it the following column:

cummulative sum
10
30
60
100

Thank you

[Reeza]

data want;

set have;

retain cum_sum;

cum_sum+value;

run;

[ilikesas]

Hi Reeza,

thanks for the answer!

It is really short but I couldn't figure it out because its not so intuitive (at least to me) because I was trying to do something like setting the first cumsum to the value itself and for the rest of values to make cumsum by adding the value to the sum( ) of the previous values and I was getting a mess...

[Reeza]

Technically you don't even need the retain statement, the + implies the retain so the following works as well:

data want;

set have;

cum_sum+value;

run;

[ilikesas]

Hi Reeza its me again,

now I would like to add another level of complexity, if I may:

assume that in the previous case I had to calculate the cumulative sum for one company, but now I need to do the same thing but for many companies, so each time I get to a new company the cumulative sum restarts calculating.

Thank you

[stat_sas · Accepted solution]

Hi,

For many companies you need by processing. Just make sure data is sorted by company variable.

data want;

set have;

by company;

if first.company then cum_sum=0;

cum_sum+value;

run;