Intro to Tableau: Line and Bar Charts

Note:

If you do not currently have Tableau, you can download a free version at: https://public.tableau.com/s/

Lines and Bar Charts

Start Tableau

When you start up Tableau, the first thing you need to do is select a data source.

In this case, select Excel and choose the file the you downloaded above (schoolLunch.xls)

Once loaded, the Data Source Page will open up.

a. Data Source File

b. Shows Sheets in the file (there is only one sheet in this particular file)

c. Shows data.

The Data

In this example, we are looking at the number of kids receiving Free, Reduced Priced, and Full Price lunches at American public schools from 1971 to 2015.

Line Chart

Start by making a new sheet

A Quick Note About Dimensions and Measures:

Notice on the new sheet that the columns from your imported Excel sheet have been placed into two boxes on the left of the screen: Dimension and Measures. Think of Dimensions as Factors or Labels. While Measures are columns you would perform calculations against (adding, averaging, etc).

Drag Year from Dimensions and Free from Measures into Columns and Rows respectively.

The line graph should appear automatically. If not, follow the next steps:

First, make sure your Row variable says SUM(Free)this means we are summing up all numbers in the Free column— If it doesn’t, hover over the measure until a small downward arrow appears. Then go to Measure and select Sum.

If you don’t have a line chart, go to Marks and select Line from the drop down menu

Bar Chart

Now, go to Marks again and select Bar. Your chart will change over to a bar chart. Try a few of the other options like Area and Shape.

Next Lesson: Dual Axis Charts

Tableau: Free and Reduced School Lunch Program

This visualization depicts Free, Reduced, and Full priced lunches served by the the National School Lunch Program (NSLP) in United States Public and Private Non-Profit Schools.

The sharp rise Free lunches, in conjunction with the sharp decline in Full priced lunches since 2008 hints that the effects of the 2008 economic recession are still being felt.

Visualization can be found at: Link to Tableau Worksheet

**Data taken from Data.gov: Link to Data File