Pie Charts - Scaling

[MK]

I have a boss that insists that it is possible to create a pie chart, and
then create another chart that is to scale of that chart. For example, I am
attempting to create a chart about revenues. Revenue essentially increased
52% between 2007 and 2008. He wants me to create a pie chart for 2007, and
then another chart for 2008 that is exactly 52% bigger. Is this possible to
do automatically? I feel like it isn't, but he is really stressing that it
has to be possible.

 

[Del Cotter]

I have a boss that insists that it is possible to create a pie chart, and
then create another chart that is to scale of that chart. For example, I am
attempting to create a chart about revenues. Revenue essentially increased
52% between 2007 and 2008. He wants me to create a pie chart for 2007, and
then another chart for 2008 that is exactly 52% bigger. Is this possible to
do automatically? I feel like it isn't, but he is really stressing that it
has to be possible.

Abusive managers are a source of many of the questions that turn up
here!

He's wrong about Excel, there's no built-in way to condition the
diameters of two pie charts on data in cells. I would strongly suggest
you just do it by hand and don't tell him. How is he going to know by
looking?

If you have to have an automatic solution, try some of the special VBA
programming tricks used by Andy Pope and Ed Ferrero. Andy's programme
sizes pie charts according to the sum of their values, and Ed's
programme turns the bubbles of a bubble chart into pies. Then you can
create a bubble chart with two bubbles, one 52% bigger than the other.

http://www.andypope.info/charts/piesizer.htm
http://www.edferrero.com/ExcelCharts/tabid/102/Default.aspx

 

[Andy Pope]

Hi,

He maybe confusing the Pie of Pie chart type and bubble charts.
Anyhow the relationship described is not a built-in feature of any chart.

Using pie charts is not normally a good idea but to then size on against
another make the problems of reading pies even worse.

Cheers
Andy

 

[MK]

Haha, that would be nice to do it by hand and tell him it was automatic. The
only problem is that he wants an automatic way for when I leave. I'm an
intern, so when I leave, they are going to have to figure out how to do it by
hand rather than just throw it my way, which is a problem for them.

 

[Jon Peltier]

As you've been reassured, there's no automatic way to do this. With a little
code you can do anything, but the question is, should you? Tufte once wrote
something like, "The only thing worse than one pie chart is several of
them."

Is the second chart supposed to be 52% larger by area, or by diameter? Human
cognition is only about 70% as good at judging areal dimensions as linear
dimensions, so whichever you choose (by area or by diameter) it will not
ever be accurately interpreted. Stacked bar or column charts are not
generally a good choice either, but I suspect if you had two stacks, using
actual revenues for each year, the relative difference in height between the
two stacks would be obvious. Worried about not being able to judge
percentages of the individual items in the stack? Well, except for 50% and
25%, you can't really judge percentages in a pie chart either, you've been
fooled into thinking that you can.

- Jon