Transcript What’s wrong NOW?! An introduction to debugging SAS

Combining Data Sets
with Character
Variables of Different
Lengths
Martha Cox
Cancer Outcomes Research Program
Cancer Care Nova Scotia
The Problem
2
data sets to combine (SET)
 They contain some of the same
character variables, but with
different lengths.
How ?
 PROC APPEND:
Uses all attributes from the base
data set.
 Data step with a SET statement:
Manually-created LENGTH
statement.
An Easier Solution
A macro that creates and then runs a
SAS program with the right
information.
Algorithm of the Macro
 Run
PROC CONTENTS for each
data set; output the metadata for
the character variables.
 Merge the results together, keeping
both lengths.
 Write a SAS program.
 Run the SAS program.
%macro union(dsn1=,
/*Name of the first data set
*/
dsn2=,
/*Name of the second data set
*/
out=
/*Name of combined data set
*/);
proc contents data=&dsn1 noprint
out=out1(keep=name type length where=(type=2));
proc contents data=&dsn2 noprint
out=out2(keep=name type length where=(type=2));
run;
data _null_;
file "combined.sas";
merge out1 out2(rename=(length=length2)) end=last;
by name;
if _n_ = 1 then put "Data &out;";
l = max(length,length2);
put "
length " name " $ " l 2. ";";
if last then do;
put "
set &dsn1 &dsn2;";
put "run;";
end;
run;
%include "combined.sas";
%mend union;
Example: The Call
– %macro(dsn1=ONE,
–
–
–
dsn2=TWO,
out=UNION
);
Example: Input Data Sets
– Contents of Data Set ONE
– Obs
– 1
– 2
NAME
c1
c2
TYPE
2
2
LENGTH
4
8
– Contents of Data Set TWO
– Obs
– 1
– 2
NAME
c1
c2
TYPE
2
2
LENGTH
3
10
Example: The Program
data union;
length c1 $ 4;
length c2 $ 10;
set one two;
run;
Example: The Result
Contents of Data Set UNION
Obs
NAME
TYPE
LENGTH
1
c1
Char
4
2
c2
Char
10
Reference
 Authored
by Ron Cody, a SAS
Books By Users author.
 Found in the SAS Sample Library
http://support.sas.com/notes/index.html
Questions ?