Syntax to Auto relable, with specific labeling for duplicates

[sb]

Hello,

I have a dataset with case ID's that are unique to the project, which need to be kept. However, there are cases that have the same ID, which also need to be kept. I want to create a new id that will number the cases 1 - 4000, however, utilize the same ID for the duplicates. This would show the total number of cases, not including duplicates.

For example:
 ID      New ID
x20      1
x25     2
x30     3
x30     3
x30     3
x35     4
x40     5

Any suggestions on how to do this easily with syntax? I have 4000 cases & would prefer to not do it by hand & avoid any mistakes.
Thanks!
-Sherah

[Andy W]

This is a FAQ, see example syntax below.

**********************************.
SORT CASES BY Id.
DO IF $casenum = 1.
  COMPUTE NewId = 1.
ELSE IF Id = LAG(ID).
  COMPUTE NewId = LAG(NewId).
ELSE.
  COMPUTE NewId = LAG(NewId) + 1.
END IF.
EXECUTE.
**********************************.

[David Marso]

See LAG function.

IF $CASENUM EQ 1 New_ID=1.
IF ID EQ LAG(ID) New_ID=LAG(New_ID) .
IF MISSING(New_ID) New_ID=LAG(New_ID) + 1.

OR:

COMPUTE New_ID=SUM(LAG(New_ID),MAX(ID NE LAG(ID), $CASENUM EQ 1)).
HTH.
---

sb wrote

Hello,

I have a dataset with case ID's that are unique to the project, which need to be kept. However, there are cases that have the same ID, which also need to be kept. I want to create a new id that will number the cases 1 - 4000, however, utilize the same ID for the duplicates. This would show the total number of cases, not including duplicates.

For example:
 ID      New ID
x20      1
x25     2
x30     3
x30     3
x30     3
x35     4
x40     5

Any suggestions on how to do this easily with syntax? I have 4000 cases & would prefer to not do it by hand & avoid any mistakes.
Thanks!
-Sherah

[sb]

Perfect! The second method you supplied worked just as I hoped!
Thank you for your quick & thorough response!
-Sherah

[sb]

Thank you for your help! I had made several efforts to find the information, but must have been wording it incorrectly. Thank you for your quick reply!