topic Nested Loop problem in SAS Programming

Nested Loop problem

forumsguy — Fri, 09 Mar 2012 20:34:24 GMT

Hi,

My basic question is to produce dataset based on 3 loops from our central repository. My desired output should be like this

Id1	Id2	Id3	Id4

1	1	100	I1
		200	I2
		300	I3
		400	I4
		500	I5
		600	I6
2	2	1100	I7
		1200	I8
		1300	I9
		1400	I10
		1500	I11
		1600	I12
3	3	2100	I13
		2200	I14
		2300	I15
		2400	I16
		2500	I17
		2600	I18

So I want to loop Id1 3 times thats my outermost loop, Id2 3 times thats my first inner loop and then Id3 and Id4 6 times each... I am able to produce output for Id1 but the only thing I M getting confused about is where to apply ends for inner loops and where to apply output statement... Guess my C background is making me confused... Any suggestions would be really helpful

Nested Loop problem

ballardw — Fri, 09 Mar 2012 20:45:20 GMT

Your example doesn't show ld2 looping but rather the same as ld1. And ld4 doesn't actually look like a loop per se.

When you say you want to create a dataset do you actuall want the values of ld1 and ld2 to be blank or did you suppress them to show the loop structure?

Re: Nested Loop problem

Tom — Fri, 09 Mar 2012 20:51:38 GMT

What you said you wanted looks like this. Not sure that it is really much different than C or any other language.

do id1=1 to 3;
  do id2=1 to 3;
    do id3=1 to 6;
      do id4=1 to 6;
        output;
      end;
    end;
  end;
end;

What you produced as a table looks more like this.

do id1=1 to 3;
  id2=id1;
  do id3loop=1 to 6;
    id3=1000*(id1-1)+100*id3loop;
    rec+1;
    id4=cats('l',rec);
    output;
  end;
end;

Re: Nested Loop problem

ballardw — Fri, 09 Mar 2012 20:57:13 GMT

Assuming the blanks were for clarity but that the ld1 and ld2 variables are actually in the data this produces data as your example.

data junk (drop= count t);
   count=0;
   do ld1 = 1 to 3;
      ld2 = ld1;
      t= (ld2-1) * 1000;
      do ld3 = (t+100) to (t+600) by 100;
         count+1;
         ld4= cats('l',put(count,f2.0));

         output;
      end;
   end;
run;