topic Re: Multiple variables with null values in New SAS User

Multiple variables with null values

dikshar — Wed, 16 Jan 2019 23:14:29 GMT

I am working with a dataset that has a about 10 variables for different treatments. If a patient underwent a particular treatment, then that treatment's variable has a date and the rest of the treatment variables are null. I want to make a new variable so that whichever treatment a patient underwent, the corresponding value is posted to a new variable.

Example:

Obs TrtA TrtB3 TrtGh TrtE8

1 . 01/01/2019 . .

2 . . 01/04/2019 .

3 . 01/12/2019 . .

I want the output to look like:

Obs Trt_date

1 01/01/2019

2 01/04/2019

3 01/12/2019

I am completely stuck after trying multiple if statements, treating each variable individually and together, and nothing is working. Please help!

Re: Multiple variables with null values

Reeza — Wed, 16 Jan 2019 23:26:50 GMT

Have you tried the COALESCE() function?

@dikshar wrote:

I am working with a dataset that has a about 10 variables for different treatments. If a patient underwent a particular treatment, then that treatment's variable has a date and the rest of the treatment variables are null. I want to make a new variable so that whichever treatment a patient underwent, the corresponding value is posted to a new variable.

Example:

Obs TrtA TrtB3 TrtGh TrtE8

1 . 01/01/2019 . .

2 . . 01/04/2019 .

3 . 01/12/2019 . .

I want the output to look like:

Obs Trt_date

1 01/01/2019

2 01/04/2019

3 01/12/2019

I am completely stuck after trying multiple if statements, treating each variable individually and together, and nothing is working. Please help!

Re: Multiple variables with null values

ballardw — Wed, 16 Jan 2019 23:28:57 GMT

If your description that only one of the trt variables has value then this should work:

data want;
  set have;
  array t{10} trtb3 trtgh trte8 <finish the list>;
  trt_date = max( of t(*));
  format trt_date mmddyy10.;
run;