Counting a fixed variable

[farshidowrang]

Dear programmers,

How can I count a fixed variable in an easy way?

What I have is:

WELL_NAME

A

A

A

A

A

A

A

A

A

B

B

C

C

C

C

C

C

C

C

D

D

E

E

E

E

E

E

F

F

F

F

F

F

F

F

What I want is:

WELL_NAME	COUNT
A	1
A	2
A	3
A	4
A	5
A	6
A	7
A	8
A	9
B	1
B	2
C	1
C	2
C	3
C	4
C	5
C	6
C	7
C	8
D	1
D	2
E	1
E	2
E	3
E	4
E	5
E	6
F	1
F	2
F	3
F	4
F	5
F	6
F	7
F	8

Best regards

Farshid 

[Tom · Accepted solution]

Simple application of BY group processing.

data want;
  set have;
  by well_group;
  count+1;
  if first.well_group then count=1;
run;

[farshidowrang]

Thank you very much my friend!

Best regards

Farshid

[Reeza]

This outlines how you can do this:

https://stats.idre.ucla.edu/sas/faq/how-can-i-create-an-enumeration-variable-by-groups/

[farshidowrang]

Thank you!