Repeated data

[Barkamih]

A
17.93
17.93
17.93
17.93
17.93
17.93
23.29
23.29
23.29
23.29
24.00
24.00
24.00
24.00
8.718
8.718
8.718
8.718
24.17
24.17
24.17
24.17
24.17
24.17
13.75
13.75
13.75
13.75

Hi guys 

In this variable A repeated numbers, I would like to keep only one appearance of each number, and the rest I should have a missing value. 

my data set has this name P1FD

my best regards 

Ibrahim 

[PeterClemmensen · Accepted solution]

Like this?

data have;
input A;
datalines;
17.93
17.93
17.93
17.93
17.93
17.93
23.29
23.29
23.29
23.29
24.00
24.00
24.00
24.00
8.718
8.718
8.718
8.718
24.17
24.17
24.17
24.17
24.17
24.17
13.75
13.75
13.75
13.75
;

data want;
 set have;
 by A notsorted;
 if not first.A then A=.;
run;