topic Re: if first. and last observations in SAS Programming

if first. and last observations

lerdem — Fri, 02 Oct 2015 18:48:08 GMT

i have table as below

Type course crn meetday meettime NEW COLUMN

2 MAT20 215 MW 09

4 MAT20 154 MW 08 .

4 ACG15 214 T 12 1

4 ACG15 214 MW 12 2

This is an example table. I have first 5 variables 'Type, course, crn , meetday and meettime' I need to add 'new column'.

If course and crn are same , but meetday or meettime different then new column should show the number.

Re: if first. and last observations

Astounding — Fri, 02 Oct 2015 18:53:13 GMT

This should do it. Assuming that you have already sorted your data in a way that groups all the course/crn combinations:

data want;

set have;

by course crn notsorted;

if first.crn then do;

if last.crn then new_column=.;

else new_column=1;

run;

else new_column + 1;

run;

Re: if first. and last observations

lerdem — Fri, 02 Oct 2015 19:21:14 GMT

Thank you but it is not clear

Re: if first. and last observations

Astounding — Fri, 02 Oct 2015 19:37:19 GMT

Well, there are some programming techniques that you may need to know:

BY statement in a DATA step
NOTSORTED
varname + 1

Are you asking about those, or are you asking about sorting your data, or are you asking about something else entirely?

Re: if first. and last observations

lerdem — Fri, 02 Oct 2015 19:40:41 GMT

no actually, when i use your code it doesn't work. gives error. Should i change somethink?

Re: if first. and last observations

Reeza — Fri, 02 Oct 2015 19:55:19 GMT

What error do you receive? What code did you use? Saying you have an error isn't helpful for debugging.

Re: if first. and last observations

MikeZdeb — Fri, 02 Oct 2015 23:53:46 GMT

Hi, another suggestion ...

data x;
input type course :$5. cm meetday:$2. meettime;
datalines;
2 MAT20 215 MW 09
4 MAT20 154 MW 08
4 ACG15 214 T   12
4 ACG15 214 MW 12
;

data y;
do new_column=1 by 1 until (last.cm);
   set x;
   by course cm notsorted;
   if first.cm and last.cm then call missing (new_column);
   output;
end;
run;

data set y ...

new_
Obs column type course cm meetday meettime

1        .        2     MAT20     215      MW           9
2        .        4     MAT20     154      MW           8
3        1        4     ACG15     214      T           12
4        2        4     ACG15     214      MW          12