5 Replies Latest reply on Nov 11, 2018 9:25 PM by nikki.solanki.0

    New User - Combining Multiple Time Series From Multiple Files?

    nikki.solanki.0

      I am a new Tableau user trying to get some pointers in combining time-series data, would greatly appreciate any assistance.

       

      My dataset:

      • 9 different vitals collected at every 1 second from different wearable devices --> ~2.5M datapoints/vital/month. I have 4-month sample data for one user, both timeline and the number of users will grow soon.
      • Each vital is collected with timestamp + vital value + a unique counter. Each vital is stored in a separate file for a given month --> 9 files/month.
      • I'd like to plot all 9 vitals side-by-side (X-axis) along a 24-hour period (Y-axis).
      • There are gaps in data which vary by vital (depending upon device battery and other factors).

       

      Questions:

      • What is the best way to combine all data (Join, Union, something else?) to display on a single dashboard?
      • Tried to join data but that is severely limiting available data as it is ONLY taking time periods where data is available from ALL 9 devices (a problem as some device or the other always have data gaps on a daily basis).
      • Tried to plot multiple graphs w/o joining but getting an error (to plot on the same Y-axis which is time).
      • With Union, I am getting similar restriction as Join for some reason?

       

      Any pointers? Many thanks.

        • 1. Re: New User - Combining Multiple Time Series From Multiple Files?
          Simon Runc

          Hi Nikki,

           

          So one way that might help will be to use a UNION, with a twist!

           

          In the below GIF I've unioned 2 files (heart rate and blood-pressure) and then used the "Merge Fields" so that I get all the Vitals into a single measure. The Table Name/Sheet (with csv this will be the File Name) can then be used (as a dimension) to split up the different values. If the TimeStamp is also called a different name in each file, you'll also need to merge these so you get a single column of all the datetimes.

           

          Union_Vitals.gif

           

          I've attached a quick example of this plotted out in Tableau. You may also want/need to normalise the values if they are of very different scales, if you want to plot them on a single axis, or you can bring the Table Name/Sheet onto the Columns and create an axis per measure.

           

          Hope that helps,

          1 of 1 people found this helpful
          • 2. Re: New User - Combining Multiple Time Series From Multiple Files?
            nikki.solanki.0

            Simon -  I am a newbie and a student so your animation definitely helped me grasp the concept very quickly! I'll try this later today and let you know.

            • 3. Re: New User - Combining Multiple Time Series From Multiple Files?
              nikki.solanki.0

              Simon - Many thanks, the Union worked as you expected. I created different sets using TableName and that works for creating individual charts, SPO2 set example below.

               

              Union.png

              My goal is to create a series of charts as you see below. My method likely is crude and won't work I am not sure how to assign different sets/filters for each chart. Note the chart below is not accurate as only takes the subset of timeframe as I described above so only including it as an illustration.

               

              Screen Shot 2018-11-10 at 7.08.54 PM.png

              What would be the optimal way to:

              The Table Name/Sheet (with csv this will be the File Name) can then be used (as a dimension) to split up the different values?
              • 4. Re: New User - Combining Multiple Time Series From Multiple Files?
                Simon Runc

                Glad it helped.

                 

                So with regards this there are 2 ways you can go here.

                 

                On the first way (shown in the GIF) I combined both the Heart Rate and Blood Pressure measures into a single column, called values. I can then use the Table Name to split up the measures into separate charts (in my example I just brought this onto the colour shelf to get a colour per Sheet Name, but just add it to the columns to get a chart per Sheet Name)

                 

                Another way, with Unioning the data, but without merging the fields (so I get a measure for each Vital), is shown on "Option 2". Here I've used the (Tableau generates) measure names/ measure values to split the charts up (these a psudo-dimensions and measures that Tableau creates for plotting multiple measures)

                 

                If the scales of the different measures are very different you can also use this option

                 

                 

                So each chart uses it's own Axis range (or you could normalised the measures, say between 0 and 1)

                 

                Hope that helps

                1 of 1 people found this helpful
                • 5. Re: New User - Combining Multiple Time Series From Multiple Files?
                  nikki.solanki.0

                  Simon,

                   

                  Once again, thank you for your assistance and appreciate your patience and coaching.

                   

                  That worked perfectly! Thanks!