In the preceding individual axes chart, we saw that, because the measures were not in the same pane, it was difficult to draw inferences by just looking at the chart and without taking the axes' values into consideration.
It would be great if, in the preceding example, we could get both the Profit and Sales in the same pane and have a unified axis for both, so that it is quicker and easier to interpret the chart. This is where we use a Blended axes chart.
As the name suggests, the axis is blended to have a common unified scale to refer to.
We will continue working in the same workbook, and we will also work with the same example that we discussed in the previous recipe, where we compared Profit and Sales across various months for all the years. Let us see how to create a Blended axes chart.
- Let us create a new sheet by pressing Ctrl + M and rename it as Blended axes chart.
- Next, we will right-click and drag the Order Date field from the Dimensions pane and drop it into the Columns shelf. This step is exactly the same as step 3 in the previous recipe. Select the MY(Order Date) option.
- We will then drag Profit from the Measures pane and drop it into the Rows shelf. Refer to the following screenshot:
- We will then Sales from the Measures pane and drop it on the Profit axis. Refer to the following screenshot:
- Once we drop the Sales field on the Profit axis, we will get the Blended axes chart, as shown in the following screenshot:
When we put the Sales field on the axis which already has Profit, we are actually Blending the Sales and Profit values to create a common axis. This common axis is now called Value. Further more, notice that the scale of the axis, which was initially showing Profit values, has now changed to accommodate the Sales values as well. The field Measure Value is placed in the Rows shelf instead of just Profit, and the field Measure Names is placed in the Color shelf.
As discussed in Chapter 1, Keep Calm and Say Hello to Tableau, Measure Names contain the names of all our measures in a single dimension, and Measure Values contain the values of all our measures in a single field; since the Measure Names field is in the Color shelf, we get to see two colored lines: the orange line represents the Sales, and the blue line represents the Profit.
In the preceding screenshot, we can quickly compare the Sales and Profit across various months and years. Further, the spike for December 2013 that we discussed in the Individual axes chart, is now much easier to read and compare.
We use Blended axes chart when two or more measures need to share an axis. In Blended axes charts, each measure is represented as a different color. The chart is most appropriate to use when comparing measures that have similar scale and units of measurement.