topic Re: Creating a Variable from multiple variables in SAS Programming

Creating a Variable from multiple variables

chavens — Sun, 23 Apr 2017 02:14:52 GMT

Hi All,

I'm trying to get the following code to work where I basically want to create the variable "time" from the largest "MosLater" variable for each participant, but the code that I'm using is just producing all blanks for some reason when creating the time variable (no errors in the log though)... Any ideas on how to get this to work?

data ad44;
set ad45;
if MosLater14=. then time=MosLater13;
else if MosLater13=. then time=MosLater12;
else if MosLater12=. then time=MosLater11;
else if MosLater11=. then time=MosLater10;
else if MosLater10=. then time=MosLater9;
else if MosLater9=. then time=MosLater8;
else if MosLater8=. then time=MosLater7;
else if MosLater7=. then time=MosLater6;
else if MosLater6=. then time=MosLater5;
else if MosLater5=. then time=MosLater4;
else if MosLater4=. then time=MosLater3;
else if MosLater3=. then time=MosLater2;
else if MosLater2=. then time=MosLater1;
run;

Thanks,

Cody

Re: Creating a Variable from multiple variables

chavens — Sun, 23 Apr 2017 02:19:44 GMT

In a different datastep, I already created the variable time via the code: time=MosLater14;

Re: Creating a Variable from multiple variables

PGStats — Sun, 23 Apr 2017 02:27:49 GMT

data ad44;
set ad45;
time = max(of MosLater1-MosLater14);
run;

Re: Creating a Variable from multiple variables

Reeza — Sun, 23 Apr 2017 02:33:39 GMT

Coalesce()?

Edit: by largest do you mean the largest value across or the largest MOS variable? It appears the latter according to your code but the former according to your question.

Re: Creating a Variable from multiple variables

Patrick — Sun, 23 Apr 2017 03:09:55 GMT

Given your narrative and especially your code it looks to mee that you don't want to pick the largest value from the MosLater variables (that's what @PGStats code does) but you want to pick the first non-missing value from a variable list ordered descending from 14 to 1 (MosLater14 - MosLater1). That's what below code does.

data have;
  array MosLater {14};
  do _i=1 to dim(MosLater);
    MosLater[_i]=ceil(ranuni(1)*100);
    output;
  end;
  drop _i;
  stop;
run;

data want;
  length time 8.;
  set have;
  time = coalesce(of MosLater14-MosLater1);
run;

Change history:

Code amended based on @Reeza's comment (removal of array statement).

Re: Creating a Variable from multiple variables

chavens — Sun, 23 Apr 2017 02:45:41 GMT

I did mean to pick the biggest of the MosLater variable. If MosLater5 was the first missing then 6-14 would also be missing (and also 3<4<5<6...etc). I just could not think of how to do that initially, thus the confusing and inefficient code.

Thanks!

Re: Creating a Variable from multiple variables

Reeza — Sun, 23 Apr 2017 02:50:12 GMT

Using Patricks code, but you can skip the array declaration, unless you're using it elsewhere.

time2 = coalesce(of MosLater14-MosLater1);