Line charts connect related marks in a visualization to show movement or relationship between those connected marks. The position of the marks and the lines that connect them are the primary means of communicating the data. Additionally, you can use size and color to communicate additional information.
The most common kind of line chart is a Time Series. A time series shows the movement of values over time. Creating one in Tableau requires only a date and a measure.
Continue your analysis of Superstore sales using the Chapter 01 Starter workbook you just saved:
- Navigate to the Sales over time sheet.
- Drag the Sales field from Measures to Rows. This gives you a single, vertical bar representing the sum of all sales in the data source.
- To turn this into a time series, you must introduce a date. Drag the Order Date field from Dimensions in the data pane on the left and drop it into Columns. Tableau has a built-in date hierarchy, and the default level of Year has given you a line chart connecting four years. Notice that you can clearly see an increase in sales year after year:
- Use the drop-down menu on the YEAR(Order Date) field on Columns (or right-click the field) and switch the date field to use Quarter. You may notice that Quarter is listed twice in the drop-down menu. We'll explore the various options for date parts, values, and hierarchies in the Visualizing Dates and Times section of Chapter 3, Venturing on to Advanced Visualizations. For now, select the second option:
Notice that the cyclical pattern is quite evident when looking at sales by quarter:
