topic Re: Breaking logic of using if ? in SAS Programming

Breaking logic of using if ?

Phil_NZ — Fri, 05 Mar 2021 09:31:59 GMT

Hi all SAS Users,

1. I get something wrong with my logic.

I have the variables cshtrd and prccd_abs_ are numeric variables, the summary is as below

I want to generate a variables named dollar_vol= cshtrd*prccd_abs_

My code is

Comment trading volume*unadjusted price (converted to USD)< 100$ 
then set missing ;

if cshtrd*prccd_abs_ <100 and n(cshtrd,prccd_abs_)=2 
		then dollar_vol=.;
		else dollar_vol=cshtrd*prccd_abs_;

And the log says that ( I just post lines 37 and 39 because they are relevant to the NOTE)

37         		if cshtrd*prccd_abs_ <100 and n(cshtrd,prccd_abs_)=2
38         		then dollar_vol=.;
39         		else dollar_vol=cshtrd*prccd_abs_;

NOTE: Missing values were generated as a result of performing an operation on missing values.
      Each place is given by: (Number of times) at (Line):(Column).
      176040 at 37:12   176040 at 39:25

I am wondering what I did wrong in my calculation and is there any hint to fix it?

Warm regards.

Re: Breaking logic of using if ?

Shmuel — Fri, 05 Mar 2021 09:32:30 GMT

The log message:

NOTE: Missing values were generated as a result of performing an operation on missing values

and later it points to log line 37 where the code is:

if cshtrd*prccd_abs_  ....

means that either CSHTRD or PRCCD_ABS or both contain missing value, therefore the result is missing value.

You have to decide if you want to deal with this case in a different way and code your program appropriately.

Re: Using double if

Phil_NZ — Fri, 05 Mar 2021 09:40:37 GMT

Thank you @Shmuel

After changing to double if, the error note no longer exists, and after checking mean, the results from the old and new code are the same for variable dollar_vol

if n(cshtrd,prccd_abs_)=2 then if cshtrd*prccd_abs_ <100 /*chnaged line*/
		then dollar_vol=.;
		else dollar_vol=cshtrd*prccd_abs_;

Thank you!