sas base question

[ravikiran2627]

i have a dataset 

data xxx;

id gender

1      M

2      M

3      M

4      M

5      F

6      F

7      F

8      F

i need the output this way

id gender

1      M

2      F

3      M

4      F

5      M

6      F

7      M

8      F

how to do it in base sas.. can anyone hep me out in this pls

[Kurt_Bremser]

Set gender depending on mod(_n_,2).

[Astounding]

Should ID really change just because the order of the observations changes?

Here is an approach that works but doesn't change ID. It requires that your data contains equal numbers of M and F values:

Data want;
Set have (where=(gender="M"));
output;
Set have (where=(gender="F"));
output;
run;

The ID can be recomputed if necessary. Instead of

1 2 3 4 5 6 7 8

you will get

1 5 2 6 3 7 4 8

It's not clear which set of ID values would be more useful. Perhaps there should even be a third variable added to the new data set so you would both the original order and the new order available.

[Ksharp]

 

data xxx;
input id gender $;
drop id;
cards;
1      M
2      M
3      M
4      M
5      F
6      F
7      F
8      F
;
data temp;
 set xxx;
 by gender notsorted;
 if first.gender then n=0;
 n+1;
run;
proc sort data=temp;
by n descending gender ;
run;
data want;
 set temp;
 id+1;
run;