5 Replies Latest reply on Sep 20, 2013 1:01 PM by Michael Lamont

# Calculating Timeline of First User Login [.twbx attached]

I am attempting to create a timeline of first time user logins to our system.  The data is structured like this:

 date user-ident activitycode 13-Aug-13 29246 70 13-Aug-13 30226 70 13-Aug-13 31360 70 13-Aug-14 33250 70 13-Aug-14 36246 70 13-Aug-15 42798 70 13-Aug-16 62342 70 13-Aug-16 74914 70 13-Aug-17 78302 70 13-Aug-17 88592 70

The goal is a timeline that shows net new user logins per day.  Using Count Distinct of user-ident (unique # for every user) I can see the unique number of users logging in for a certain day, but that means when I do a running sum of CNTD users the total number adds up the sum of each day when what I want is the total unique users for the time whole time period.

The question I'm trying to answer is "how many new user registrations have I had over the last X days/months/years" as well as "on this day we had X new user registrations."

I'm thinking this is accomplished by some combination of a table calculation and/or calculating the first instance of a users recorded activity.  At this point I'm stumped though.

Any help or thoughts would be great. Thank you.  Packaged workbook is attached using cleansed data.

• ###### 1. Re: Calculating Timeline of First User Login [.twbx attached]

This seems to be more of an issue with the organization of your data.  Is your data kept in Excel?  Do you regularly maintain that file or is that file automatically generated for you?  If it's something you maintain, it'd be easy enough to create a separate sheet that identifies the first login date for each userid.  Then, you easily generate the views you want in Tableau using this sheet instead of the one you're trying to use now.

• ###### 2. Re: Calculating Timeline of First User Login [.twbx attached]

This is just a small snippet of data from a larger relational DB that has millions of rows and tens of thousands of users.  Unfortunately I don't have the power to restructure the data and it's sheer volume makes any kind of manual operation out of the question.

I'm convinced there has to be a way to identify the first login activity for a user and then plot that as a mark on the day it happened against a time axis without it being recalculated and rendered on every new day.

Again, thanks for taking the time to respond.

• ###### 3. Re: Calculating Timeline of First User Login [.twbx attached]

This is one of the definitive threads for "rolling count d":