problems with the lag() function

[deleted_user]

Hi,
here's my problem: I want to compare an observation in the second row with an observation in the first row. E.g :
fruit Fruit1 (I want to create that variable)
1 orange apple
2 apple banana
3 banana

I know with the LAG() function you can compare with the next row. Is there any function doing the same thing but with the previous row??

thanks,

Jean-Sebastien

[Nancy_B]

Hi Jean-Sebastien,

Try something like this (not tested):

data new;
merge fruits fruits (firstobs=2 rename=(fruit=fruit1));
run;

Hope this helps,
Nancy

[TobyDunn_hotmail_com]

In SAS there is no lead function. You could reverse sort your data and then use the lag function or you could create your own code to mimic the lead function:


Eaxample:


Data Have ;
Infile Cards ;
Input ID Fruit $ ;
Cards ;
1 Apple
2 Orange
3 Banana
;
Run ;

Data Need ;
Set Have NObs = NObs End = EOF ;

MyPoint = _N_ + 1 ;

If ( MyPoint <= NObs ) Then Do ;
Set Have ( Keep = Fruit Rename = ( Fruit = OldFruit ) ) Point = MyPoint ;
End ;

If Eof Then Call Missing( OldFruit ) ;

Run ;

Proc Print
Data = Need ;
Run ;