To generate sequence number on the basis of transaction

Hi Experts,

I have a scenario where i have to generate a column Sequence for field Transaction.

For eg:

If input is

TransactionID

T1

T1

T1

T2

T2

T3

then output will be as shown:

TransactionID  Sequence

T1                         1

T1                         2

T1                         3

T2                         1

T2                         2

T3                         1

Please suggest some transform to implement above scenario.

Thanks,

Neha Khetan