topic A little help with Arrays in SAS Programming

A little help with Arrays

ManitobaMoose — Thu, 01 Mar 2018 01:10:16 GMT

Hi,

I need to specify when any one of the Questions is a 5 (the questions range from 1 to 5), using arrays. Unfortunately, the program I have written doesn't work. Perhaps someone can offer some assistance. Thanks.

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Libname Learn'/folders/myfolders/Learn' ;

Data Survey2 ;
   Set Learn.Survey2 ;
   Array QuesNum(*) $ Ques1-Ques5 ;
    do i = 1 to dim(QuesNum) ;
    end ;
    MaxQues = Max(of QuesNum) ;
    If MaxQues = 5 then Any = 'Yes' ;
    Else Any = 'No' ;
run ;

Re: A little help with Arrays

Astounding — Thu, 01 Mar 2018 02:15:02 GMT

Questions for you to get started:

Are you certain that QUES1 through QUES5 are the names of the variables you will be working with?

Do you know whether they are character or numeric?

Re: A little help with Arrays

Shmuel — Thu, 01 Mar 2018 02:17:18 GMT

1) The line MaxQues = Max(of QuesNum) ; is erronous, as MAX function needs a variable as argument

while QuesNum is an array name and not a avriable.

2) Why do you use the max function is not clear !

3) You closed the DO loop with END without having any code inside.

I assume you want to check - either i=5 or QuestNum(i)=5 and then

assign the Any variable to YES or NO.

That should be inside the do loop (i.e. between the DO statement and the END statement).

4) Your input is in one row of 5 variables: Ques1 - Ques5.

You defined only one new variable ANY.

You need either define ANY1 - ANY5 as a new array and assign the YES/NO to ANYX(i)

assuming Array anyx any1-any5;

or add OUTPUT; statment to result in 5 output rows

Re: A little help with Arrays

Reeza — Thu, 01 Mar 2018 03:08:45 GMT

MaxQues = Max(of QuesNum(*)) ;

You should also check the WHICHN function, and you don't necessarily even need an array declaration in this case.

Find5 = WHICHN(5, of ques1-ques5);
MaxQuest = max(of ques1-ques5);

Relevant section of the documentation that explains variable lists and all the variations, table at the bottom is handy:

http://documentation.sas.com/?docsetId=lrcon&docsetTarget=p0wphcpsfgx6o7n1sjtqzizp1n39.htm&docsetVersion=9.4&locale=en

Re: A little help with Arrays

ManitobaMoose — Thu, 01 Mar 2018 05:24:35 GMT

Ok, I figured it out. Thanks for your help.

Here is my solution:

Libname Learn'/folders/myfolders/Learn' ;

Data Survey2 ;
   Set Learn.Survey2 (rename=
                       (Ques1 = CharQues1
                         Ques2 = CharQues2
                         Ques3 = CharQues3
                         Ques4 = CharQues4
                         Ques5 = CharQues5)) ;

   Q1 = Input(CharQues1, 8.) ;
   Q2 = Input(CharQues2, 8.) ;
   Q3 = Input(CharQues3, 8.) ;
   Q4 = Input(CharQues4, 8.) ;
   Q5 = Input(CharQues5, 8.) ;

   Array QuesNum(*) $ Ques1-Ques5 ;
    do i = 1 to dim(QuesNum) ;
    end ;
    Array AnyX(*) Q1-Q5 ;
    do i = 1 to dim(AnyX) ;
    If Max(of Q1-Q5) = 5 then Any5s = 'Yes' ;
    Else Any5s = 'No' ;
    end ;
    drop i CharQues1-CharQues5 Ques1-Ques5 ;
run ;

Re: A little help with Arrays

Shmuel — Thu, 01 Mar 2018 09:06:38 GMT

You can shorten your code to:

Libname Learn'/folders/myfolders/Learn' ;

Data Survey2 ;
    Set Learn.Survey2;
        retain Any5s 'No' ;                     
        length Q1-Q5 3  Any5s $3 ;
    
    Array QuesNum(*)  $ Ques1-Ques5 ;
    Array Qx(*)  Q1-Q5 ;
	
    do i = 1 to dim(QuesNum) ;
	 Qx(i) = input(QuesNum(i));      
	 if Qx(i) = 5 then Any5s = 'Yes' ;
         /* next 2 lines are for debug only - check in the log */
            Q = Qx(i);
            PUT i=  Q= Any5s= ;
    end ;
    
    drop i Ques1-Ques5 ;
run ;

or even shorter to:

Libname Learn'/folders/myfolders/Learn' ;

Data Survey2 ;
    Set Learn.Survey2;
        length Q $8   Any5s $3 ;
        retain Any5s 'No ' ;                     
    
    Array QuesNum(*)  $ Ques1-Ques5 ;
	
    do i = 1 to dim(QuesNum) ;
       if QuesNum(i) = '5' then Any5s = 'Yes' ;
         /* next 2 lines are for debug only - check in the log */
            Q = QuesNum(i);
            PUT i=  Q= Any5s= ;
    end ; 
    drop i Ques1-Ques5 ; 
run ;

run and compare the two solutions.

Re: A little help with Arrays

RW9 — Thu, 01 Mar 2018 09:17:26 GMT

Way too overthought that, you are simply searching for "5" in some variables so:

data survey2;
  set learn.survey2;
  any=ifc(index(cats(of ques:),"5"),"Yes","No");
run;

What this does is the cats puts all the variables together, index returns >0 if 5 is found, if that is true (any non zero is true) then use test Yes, otherwise use text no.