Chapter 22: Creating Sparkline Graphics
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Using the transformed data, we created Win/Loss Sparklines to visualize the results. This
approach is better than the original, but it doesn’t convey any magnitude differences. For
example, you can’t tell whether the student missed the goal by 1 page or by 500 pages.
Figure 22.11 shows a better approach. Here, we transformed the original data by subtract-
ing the goal from the pages read. The formula in cell B31 is as follows:
=B6-$C$2FIGURE 22.11
The axis in the Sparklines represents the goal.
We copied this formula to the other cells in the B31:G38 range and created a group of Line
Sparklines with the axis turned on. We also enabled the Negative Points option so that
negative values (failure to meet the goal) clearly stand out.
Specifying a Date Axis
Normally, data displayed in a Sparkline is assumed to be at equal intervals. For example,
a Sparkline might display a daily account balance, sales by month, or profits by year. But
what if the data isn’t at equal intervals?
Figure 22.12 shows data, by date, along with a Sparklines graphic created from column B.
Notice that some dates are missing, but the Sparkline shows the columns as if the values
were spaced at equal intervals.