topic Re: Why while extracting column names is changing sequence? in SAS Programming

Why while extracting column names is changing sequence?

Kaushik1 — Mon, 28 Jan 2019 10:48:57 GMT

I am trying below code-

Columns in data(new) are in the following format- A, B, E, F, C, D.

Data new;
input A B E F C D;
datalines;
1 2 3 4 6 5
2 4 6 7 8 6
1 3 4 5 3 7
4 6 2 1 3 7
1 4 9 7 2 3
;

but while getting contents the sequence is changing.

i.e. data(new1) is consisting columns of of data(new) in the following format- A, B, C, D, E, F.

proc print data=new;run;
proc contents data=new out=new1(keep=NAME) noprint;
run;
proc print data=new1;run;

Question- Why it is changing the sequence?

If I required data(new1) in the same format then what should I do?

Re: Why while extracting column names is changing sequence?

RW9 — Mon, 28 Jan 2019 10:43:49 GMT

If you look at sashelp.vcolumn - which is basically what you are printing, you will see the column name, label, length etc. as metadata. One of the columns in there is varnum. This defines the actual order, but the data is sorted alphabetically by default. So you can just sort by using the orderby option:

http://support.sas.com/documentation/cdl/en/proc/65145/HTML/default/viewer.htm#p0b3vc5qd4rg06n1g6ds45cgbke2.htm

Re: Why while extracting column names is changing sequence?

Kaushik1 — Mon, 28 Jan 2019 10:56:58 GMT

Tried following-

proc contents data=new order=varnum out=new1(keep=Name);
run;
proc print data=new1;run;

Not getting sequence in original form in data(new1).

Re: Why while extracting column names is changing sequence?

RW9 — Mon, 28 Jan 2019 11:21:12 GMT

Please avoid bad coding practices such as missing run off and putting run on same line, make code as easy to read as possible.

data new;
  input a b e f c d;
datalines;
1 2 3 4 6 5
2 4 6 7 8 6
1 3 4 5 3 7
4 6 2 1 3 7
1 4 9 7 2 3
;
run;

proc contents data=new order=varnum out=new1(keep=Name);
run;

proc print data=new1;
run;

Results in:

...


                                    Variables in Creation Order
 
                                   #    Variable    Type    Len

                                   1    a           Num       8
                                   2    b           Num       8
                                   3    e           Num       8
                                   4    f           Num       8
                                   5    c           Num       8
                                   6    d           Num       8
                                          The SAS System        11:10 Monday, January 28, 2019   2

                                           Obs    NAME

                                            1      a  
                                            2      b  
                                            3      c  
                                            4      d  
                                            5      e  
                                            6      f

In section 1 you will see the variables ordered as per the creation order.

If you want the print to display in that order, then you need to sort the dataset:

data new;
  input a b e f c d;
datalines;
1 2 3 4 6 5
2 4 6 7 8 6
1 3 4 5 3 7
4 6 2 1 3 7
1 4 9 7 2 3
;
run;

proc contents data=new out=new1 (keep=varnum name) noprint;
run;

proc sort data=new1;
  by varnum;
run;

proc print data=new1;
  var name;
run;

And you can ditch the proc compare totally and just report out the metadata like:

data new;
  input a b e f c d;
datalines;
1 2 3 4 6 5
2 4 6 7 8 6
1 3 4 5 3 7
4 6 2 1 3 7
1 4 9 7 2 3
;
run;

proc sort data=sashelp.vcolumn out=new1 (keep=name);
  by varnum;
  where libname="WORK" and memname="NEW";
run;

proc print data=new1;
  var name;
run;

Thats generally more effective than proc contents then report.