Hi everyone. Recently i was asked by apprentice about SAS function end=eof and to my shocking, i know nothing about this.
Upon Google search, i only managed to find 1 PDF file about end of file but i still dont understand the purpose of it.
The link is :
http://support.sas.com/resources/papers/proceedings09/074-2009.pdf
Does anyone have a better explanation or elaboration of end=eof ? I have never used that in my life.
You can specify end=eof in the set statement. Eof will then be a binary variable (0/1) with the value 1 for the last observation in the data set and 0 otherwise. Eof is automatically dropped. However, for demonstrational purposes, I assign the value to another variable var below. See the example below
data test;
set sashelp.class end=eof;
var=eof;
run;
proc print data=test;
run;
This enabled you to eg. keep only the last observation in a data set like this
data test2;
set sashelp.class end=eof;
if eof=1;
run;
You can specify end=eof in the set statement. Eof will then be a binary variable (0/1) with the value 1 for the last observation in the data set and 0 otherwise. Eof is automatically dropped. However, for demonstrational purposes, I assign the value to another variable var below. See the example below
data test;
set sashelp.class end=eof;
var=eof;
run;
proc print data=test;
run;
This enabled you to eg. keep only the last observation in a data set like this
data test2;
set sashelp.class end=eof;
if eof=1;
run;
Thanks for the clear explanation and sample.
To my understanding, this would be the only purpose of using end=eof right?
No. But it is a classic use of the end= Option 🙂
Sometimes users want to keep all observation except the last one. Also a nice use for the End= Option.
There are multiple uses for this. Imagine you need to write a csv where the last line is expected to hold the number of records only:
data _null_;
file "myoutfile.csv" dlm=',' dsd;
set sashelp.class end=eof;
retain recordcount 0;
if _n_ = 1 then put 'name,sex,age,height,weight';
put name sex age height weight;
recordcount + 1;
if eof then put recordcount;
run;
@imdickson wrote:
Thanks for the clear explanation and sample.
To my understanding, this would be the only purpose of using end=eof right?
There are quite a few use cases for the end= dataset option. You use it whenever something needs to happen when reading the last observation from table(s). Below another common use case.
data demo;
do while(not eof);
set sashelp.class end=eof;
output;
end;
stop;
run;
Hi @imdickson
I have a comment as a supplement to @PeterClemmensen 's good explanation. You will get a lot of hits in google, if you search for "sas end = dataset option" instead.
The SAS END= dataset option can take any valid SAS variable name as argument. The use of "eof" (end-of-file) as variable name is a tradition from way back, but not part of the syntax, so this works the same way;
data a;
do i = 1 to 10; output;
end;
data b; set a end=last_observation;
if last_observation then put i=;
run;
If a data step has more than one Set statement, it is often useful to have a check for last observation in each statement, which requires different variable names.
Please not that I do not recommend using that particular combination: end=eof
Because eof is also an option for a set statement which
As is eov
@sustagens please start a new thread for this question. That way, we keep different subjects apart and help future users. Thank you
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