Division of variables returns empty cell

[mitrakos]

Hi Everyone,

I have a proc sql table that outputs the dataset below: 

proc sql; 
create table testtable as
	select sum(numerator) as n, 
	sum(denominator1) as d1,
	sum(denominator2) as d2, 
	sum(denominator3) as d3, 
	sum(denominator4) as d4
	from work.responserate_sex;
quit;

Which outputs as: 

n	d1	d2	d3	d4
93	66	.	3	.

I am trying to create a new variable called result which would be written as 
result = n / ((d1 + d2) - (d3) + (d4))

data testtable;
set testtable;
result = n / ((d1 + d2) - (d3) + (d4));
run;

this outputs a blank cell for the new variable result and I'm not sure why. Can anyone help me out as to why this may be the case?  

[Reeza · Accepted solution]

When you sum missing values with the sum operator it returns missing. If you use the SUM() function then it returns a value.

9 + . = . for sum operator (+)
Sum(9, .) = 9 for sum function.


result = n / sum(sum(d1, d2), - 1*d3, d4));

[mitrakos]

I see! This worked perfectly. Thank you!!