2 Replies Latest reply on Apr 11, 2017 7:54 PM by Michael Dreimiller

    Mapping start and end dates from two data sets

    Michael Dreimiller

      I'm relatively new at Tableau. I'm running v10.2. I'm trying to map two data sets. The first is a list of areas of study (topic) at the college where I work from the beginning of the college to present. A topic can start as a minor/certificate program and change to a major or vice versa, and it can stop being offered and then resume. So question number one is how to best organize the data. Currently I have it like this:


      Topic          Status         StartDate   EndDate

      English       Major          1911          2017

      CS              Minor          1985          1995

      CS              Major          1996          2017

      Education   Minor          1950          1960

      Education   Minor          1965          1970

      Education   Major          1971          2008

      Education   Minor          2009          2017


      I think I'd like to display that data so that each topic is a horizontal bar that changes color depending on the Status (green for major, red for minor, no color when neither a major or minor)  and the x axis is the date range from 1911 to present. All the topics would be displayed on one chart. So, using the example data above, the Education bar would be red from 1950-1960, blank from 1960-1965, red again from 1965 to 1970, and green from 1971 to present. English would be a solid green bar from 1911 to present. CS would start as red in 1985, change to green in 1996 through present.


      Question #1: Is this the best way to organize the data to do this?

      Question #2: What would I do in Tableau to generate this visualization?


      The next part is a similar data set, but its simpler. It just tracks the start and end dates for different buildings on campus. So that data sets looks like this:


      Building      StartDate  EndDate

      Olin            1930          2017

      Cummings 1970          2010


      I'm not sure the best way to map the topic data and the building data together. I think it might be best to make separate charts, one per building, that shows all the topics compared against the lifespan of one building.


      Question #3: How would I display all of the topics and one of the buildings at a time?


      Question #4: Is there a better was to display these data sets where they both complete data sets are displayed in one chart? We'd like to see if there's a correlation between topics of study and when buildings were constructed.


      -Michael C. Dreimiller

      Connecticut College

        • 1. Re: Mapping start and end dates from two data sets
          Sarah Battersby

          Hi Michael Dreimiller,


          Is this what you were looking for with the chart of majors and minors?



          You can create it with a calculated field to give you the length of time range (end time - start time) and a Gantt chart.  I've attached a twbx so that you can see how I created it.


          You should be able to do the same with the building dates to make a chart that matches.


          In terms of comparing the two, I'd start out with separate charts for each and then pair them on a dashboard and then get a sense of how complex your visualizations look and whether they work for the questions you are trying to pull out.  You could probably put both buildings and majors/minors onto one chart and just color encode separately so that it's clear that one is buildings and one is majors/minors.



          Tableau Research

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          • 2. Re: Mapping start and end dates from two data sets
            Michael Dreimiller



            That's exactly what I was looking for. Didn't occur to me to calculate the duration. Rookie mistake. Thanks!