topic Re: First occurrence logic please in SAS Programming

First occurrence logic please

Grandhi4 — Thu, 10 May 2012 14:51:39 GMT

Hi,

I have a data set in that three variables like

Boarding point Destination point Distance_KM

Delhi Mumbai 2000

Mumbai Delhi 2000

Delhi Kolkata 4000

Kolkata Delhi 4000

Mumbai Kolkata 6000

Kolkata Mumbai 6000

......... ......... .........

How to find a 'First occurrence' ?

How to do 'First. & Last.'

can any one please help me

Thanks,

Suresh

Re: First occurrence logic please

art297 — Thu, 10 May 2012 14:59:22 GMT

In your example, which records are you trying to identify and based on which factors?

Re: First occurrence logic please

Grandhi4 — Thu, 10 May 2012 15:05:22 GMT

Hi Arthur,

Boarding point or Destination point

Thanks,

Suresh

Re: First occurrence logic please

ballardw — Thu, 10 May 2012 15:10:34 GMT

I'm guessing that you're looking to get one of each boarding destination pair. So something like this maybe:

data intermediate;

length link $ 200.; /* long enough to take both boarding and destination together*/

if upcase(boarding) ge upcase(destination) then link = catx(' ',boarding, destination);

else link = catx(' ', destination,boarding);

run;

proc sort data=intermediate; by link; run;

data want;

set intermediate;

by link;

if first.link;

run;

Re: First occurrence logic please

art297 — Thu, 10 May 2012 15:35:18 GMT

I'm also just guessing what you want. If you want to know which record a city was identified as being either a boarding or destination point, you could do it using the in function with arrays. E.g.:

data have;

input Boarding_point $ Destination_point $ Distance_KM;

cards;

Delhi Mumbai 2000

Mumbai Delhi 2000

Delhi Kolkata 4000

Kolkata Delhi 4000

Mumbai Kolkata 6000

Kolkata Mumbai 6000

;

data want (keep=City Record_Number Type);

array cities(100) $;

retain cities;

set have;

if not(Boarding_point in cities) then do;

j+1;

cities(j)=Boarding_point;

Record_Number=_n_;

City=Boarding_point;

Type="BP";

output;

end;

if not(Destination_point in cities) then do;

j+1;

cities(j)=Destination_point;

Record_Number=_n_;

City=Destination_point;

Type="DP";

output;

end;

run;

proc print data=want;

run;

output

Obs Record_Number City Type

1 1 Delhi BP

2 1 Mumbai DP

3 3 Kolkata DP

Re: First occurrence logic please

shivas — Thu, 10 May 2012 16:13:59 GMT

Hi,

Try this...is this what you want(Guess)

data have1;

input Boarding_point $ Destination_point $ Distance_KM;

newvar=catx('',Boarding_point,Destination_point);

newvar1=catx('',Destination_point,Boarding_point);

xx=lag(newvar1);

if xx=newvar then output;

cards;

Delhi Mumbai 2000

Mumbai Delhi 2000

Delhi Kolkata 4000

Kolkata Delhi 4000

Mumbai Kolkata 6000

Kolkata Mumbai 6000

;

run;