tableau exercises Building Bar Charts

Bar charts are a great way to compare data across categories. In Tableau, you typically create a bar chart by placing a dimension on the Rows shelf, and a measure on the Columns shelf, or vice-versa.

A bar chart uses the bar mark type. Tableau automatically selects this mark type when the data view matches one of the two field arrangements shown below, provided the Marks type is set to Automatic. You can add additional fields on these shelves, and Tableau will not change the chart type.

Creates Vertical Bars	Creates Horizontal Bars

Alternatively, you can manually select Bar from the Marks drop-down list for any data view. For more information about bar marks, see Bar Mark.

To create a bar chart that displays total sales over a four-year period, follow these steps:

1. Connect to the Sample - Superstore data source, which is included with Tableau Desktop.
2. Drag the Order Date dimension to Columns.
   The data is automatically aggregated by year and column headers are displayed.
3. Drag the Sales measure to Rows.
   The measure is automatically aggregated as a sum and an axis is created. The column headers are moved to the bottom of the view.
   Tableau automatically selects Line as the mark type because of the date dimension.
   
4. On the Marks card, from drop-down list of view types, select Bar.
   
   This changes the view to a bar chart.
   
   The marks (bars) are vertical because the axis is vertical. The length of each mark represents the sum of the sales for that year. For example, the sum of the sales in 2014 is $733,947, which you can verify by hovering the mouse cursor over that column:
   
7. Drag the Ship Mode dimension to Color on the Marks card.
   The view shows how different shipping modes have contributed to total sales over time. The ratios seem consistent from year to year:
   
8. Drag the Region dimension to Rows, and drop it to the left of Sales to produce multiple axes for sales by region. 
   
9. If you want to view data in the West region only, you can filter out the other regions, either temporarily or permanently. To do this, drag theRegion dimension again, this time from the Data pane to the Filters shelf.
   
10. This opens the Filter [Region] dialog box. Clear the Central, East, and South check boxes, and then click OK:
Your final view should look like this:

This view gives you enough information to answer some questions about your data—for example, how has ship mode changed in the West over the four-year period. But answers only lead to more questions, and you can go on developing the view for as long as you like.