Database Reference
In-Depth Information
A couple of things are worth mentioning: The sparklines in this format are
good for comparing patterns, and not absolute values—South Africa is just
over 1% of China, and would not even show up on a chart at the same scale.
An additional point is that (as is common with sparklines) the data has been
shown superimposed on the text. Although this is an excellent space saver,
care needs to be taken that the sparkline is still visible. In this case, using a
lighter shade of gray for the text was sufficient.
The InVenTIon oF sPArKlInes
Sparklines were first introduced to the world in Edward Tufte's book,
Beautiful
Evidence
, with several implementations making their way to the world. Luckily
for us all, he never patented them, and they are now a native feature in Excel.
If the Excel functionality isn't enough for you, more features are available
in the free add-in, “Sparklines for Excel,” at
http://sparklines-excel
.blogspot.com/
.
Just as with line charts and column charts, columns can be used in sparklines.
Data bars are another visualization to be embedded inside a table, but in this
case they are used to show a single value in the cell rather than summarizing
the values of a series. Their usage on the same data set is shown in Figure 15-6.
FI g u R e 15 - 6
Databars embedded in a pivot table
Sparklines and their variations are good for summarizing values over a series,
and are often better for showing patterns rather than absolute values due to
their extremely compressed nature, whereas data bars are good for showing
absolute values.
