SETCUR Method

The following example creates a data set that contains astronomical data. You want to start iteration at RA= 18 31.6 instead of the first or last items. The data is loaded into a hash object and the SETCUR method is used to start the iteration. Because the ordered argument tag was set to YES, note that the output is sorted in ascending order.

data work.astro;
input obj $1-4 ra $6-12 dec $14-19;
datalines;
 M31 00 42.7 +41 16
 M71 19 53.8 +18 47
 M51 13 29.9 +47 12
 M98 12 13.8 +14 54
 M13 16 41.7 +36 28
 M39 21 32.2 +48 26
 M81 09 55.6 +69 04
M100 12 22.9 +15 49
 M41 06 46.0 -20 44
 M44 08 40.1 +19 59
 M10 16 57.1 -04 06
 M57 18 53.6 +33 02
  M3 13 42.2 +28 23
 M22 18 36.4 -23 54
 M23 17 56.8 -19 01
 M49 12 29.8 +08 00
 M68 12 39.5 -26 45
 M17 18 20.8 -16 11
 M14 17 37.6 -03 15
 M29 20 23.9 +38 32
 M34 02 42.0 +42 47
 M82 09 55.8 +69 41
 M59 12 42.0 +11 39
 M74 01 36.7 +15 47
 M25 18 31.6 -19 15
;

The following code sets the starting key for iteration to '18 31.6':

data _null_;
length obj $10;
length ra $10;
length dec $10;
declare hash myhash(hashexp: 4, dataset:"work.astro", ordered:"yes");
 
declare hiter iter('myhash');
myhash.defineKey('ra');
myhash.defineData('obj', 'ra');
myhash.defineDone();
call missing (ra, obj, dec);
rc = iter.setcur(key: '18 31.6');
  do while (rc = 0);
    put obj= ra=;
    rc = iter.next();
  end;
run;

The following lines are written to the SAS log.

obj=M25 ra=18 31.6
  obj=M22 ra=18 36.4
  obj=M57 ra=18 53.6
  obj=M71 ra=19 53.8
  obj=M29 ra=20 23.9
  obj=M39 ra=21 32.2

You can use the FIRST method or the LAST method to start iteration on the first item or the last item, respectively.