How to Make a Bar Chart
by: Arnel Lopez Cadelina
Bar charts are so well
accepted that they are the default chart type Tableau creates when you
double-click on a measure from within the Data pane, which is the first method
for creating a bar chart in Tableau. The bar charts were introduced in 1786 by
William Playfair in his “The Commercial and Political Atlas”. The bar charts
are being used for more than two centuries and are still an essential option
for any visual analytics project today. Playfair’s bar charts are so effective
because they leverage the preattentive attribute of height (when the chart is
in a vertical orientation) or length (when the chart is in a horizontal
orientation), which humans are extremely efficient at comparing.
In Tableau Public users can automatically produce a bar chart when a dimension is a drag to the Row shelf and measure to the Column shelf. Users can also use the bar chart option present in the Show Me button. Various types of bar charts can be created by using a dimension and a measure in Tableau.
Simple Bar Chart
From the Sample-Superstore, choose the dimension, take the sub-category to the columns shelf, and sales to the rows shelf. Shown in the screenshot below is a simple vertical bar chart.
Figure 28. Simple Bar Chart.
Bar Chart with Color Range
Colors can be applied to the bars based on their ranges. The longer bars get darker shades and the smaller bars get the lighter shades. In Tableau Public, users can do this by dragging the profit field to the color palette under the Marks Pane. If users want to distinguish the Category, drag the Category in the Marks Card and choose Color.
Swapping the Rows and Columns
In Tableau Public users can swap the rows and columns to convert the vertical bar chart to a horizontal bar chart. Users can do this by clicking the “Swap Rows and Columns” button.
Then users can convert the bar chart in ascending or descending order by clicking the “Sorted” button is shown below.
Figure 31. Horizontal Bar Chart.
Figure 33. Sorted Horizontal Bar Chart.
Stacked Bar Chart
Users can add another dimension to the bar chart to produce a stacked bar chart, which shows different colors in each bar. Drag the dimension field named segment to the Marks pane and drop it in colors. The following chart appears which shows the distribution of each segment in each bar. Stacked bars are useful when you want to understand part-to-whole relationships.
One Step Further: Add
Totals to Stacked Bars
Users can add a total label at the top of every bar even when
the bars are subdivided as in the view you just created. In the following
procedure, you will technically be adding a reference line. But by configuring
that "line" in a certain way, you end up with the labels you want.
1. From the Analytics pane, drag a Reference Line into the view and drop it
on Cell.
Figure 35. Reference Line.
2. In the Edit Line, Band, or
Box dialog box, set the aggregation for SUM(Sales) to Sum, set Label to Value, and set Line under
Formatting to None:
Figure 36. Editing the Reference
Line.
Then click OK to
close the Edit Reference Line, Band, or Box dialog box. Your view now has
currency totals at the top of each bar:
Figure 37. Stacked Bars with
Total.
You may need to adjust the view to make it look just right. If
the bars are too narrow, the numbers are truncated; to fix this, press Ctrl +
Right on the keyboard to make the bars wider. Or if you want to center the
totals over the bars—by default, they are left-aligned. Do the following:
3. Right-click any of the
totals on the bar chart and select Format.
4. In the Format window, in
the Reference Line Label area,
open the Alignment control and
select the Center option for Horizontal alignment:
Figure 38. Reference Line Alignment
Control.
