The bar graph is one of the most common data visualizations. This is because it is simply the best way of comparing the difference in value across a single item.
- Goal: Increase product subscriptions
- Question: Why does a sub set of similar products not respond as positively as others in the same market?
- Analysis: Combo chart
We will make use of the same Chapter 2 – Sales.qvf application used in the "Relationships" recipe.
- From the application overview click the button in the top right-hand corner and click the Create New Sheet button. Name this sheet
Comparison. - Once inside the newly created sheet, go to the charts asset pane
and double click the Combo chart button 
. - Add Product Group as a dimension.
- Next add Sum (Sales) as the first measure. Label it
Sales. - Add sum ([Sales Qty]) as the second measure. Label it
Sales Qty. - For the
Sales Qtymeasure:- Change the default display-format for the expression from Bars to Marker
- Right below the display format options, there is a dropdown to define the axis.
- Set the axis to secondary. Just below the axis formats there is a markers style dropdown. Select the style as Line.
- Under Sorting, promote Sales to the top of the list.
- The visualization should resemble the following image:
When it comes to comparing the magnitude of change of the values against each other, you really cannot beat a bar chart. When you need to compare multiple dimensions in the same visualization, a common approach is to stack them on top of each other. This option is available in the properties of the bar chart object.
However, this removes the length comparison we are so good at, thus making the view not as effective.
The preceding method of using symbols instead of additional bars still leaves a good focus on the comparitive length to determine the magnitude of change. This is also a more efficient use of space than creating separate visualizations to cover additional analysis.