I have simple problem, but I've not be able to get an answer from searching. I require a column to calculate the number of the nth occurrence of a value. It's best explained in this picture
I require a method to calculate column B.
I'd be very grateful for any help.
Are you looking to merely provide a count of the distinct entries of column A in column B? Or merely add a formula to come up with the table in your link?
If the latter, then the formula to write in cell B2 is:
=COUNTIF(A$2:A2,A2)
then copy/paste it down column B. Note - if your data is both a Date and Time, but the cell is formatted to only display a date, you may not get the results you want. You'd need to interject a new column with a "floor" calculation to round the date/time value to a date (Excel date times are decimal, with integer part dictating the date, and remaining 0.0 -> 1.0 dictating the time of day)
If you just want to derive a table of the counts of distinct entries in column A, then a pivot table will do this for you - simple add a pivot table to cover the data in column A, then select column A into the rows category, and then also drag it into the values category, ensuring the field is set to "Count of". You should then have a table with the distinct entries in your data set in one column, and the count of their occurrences in the other column.
Use the following formula to generate the required series:
=COUNTIF($A$1:A1,A1) and strech(copy)
it in all the cells
This will generate result like this:
A 1 COUNTIF($A$1:A1,A1)
A 2 COUNTIF($A$1:A2,A2)
C 1 COUNTIF($A$1:A3,A3)
C 2 COUNTIF($A$1:A4,A4)
B 1 COUNTIF($A$1:A5,A5)
B 2 COUNTIF($A$1:A6,A6)
A 3 COUNTIF($A$1:A7,A7)
C 3 COUNTIF($A$1:A8,A8)
D 1 COUNTIF($A$1:A9,A9)
D 2 COUNTIF($A$1:A10,A10)
D 3 COUNTIF($A$1:A11,A11)
D 4 COUNTIF($A$1:A12,A12)
You can use the COUNTIF
worksheet function, with a relative address.
Eg. In cell B2, enter this formula:
=COUNTIF(A$2:A2,A2)
And then fill-down.