In this series, we get to the heart of different chart styles to better understand how they tick, through intimate and humorous interviews with the charts themselves. Welcome to “Chart Chats”.

Today we’re talking to the Pie Chart

This week our guest is the humble pie. Thanks for coming round.

Thanks for having me.

So, what’s cooking?

My feelings are a bit divided at the moment, I’m 30% apprehensive, 60% excited and 10% a few other things but overall, I’m 100% happy to be here.

I’m sure all of our audience have come across a pie chart at some point or other. How long have you been around for?

I was invented over 200 years ago so I’ve been around for a long time. And for all you haters out there, I was invented by William Playfair –  the same guy who invented the bar, line and area charts – so there!

As you alluded to there, you’re a controversial chart in some circles. People have called you evil and the worst chart in the world, and there is even a movement dedicated to ‘kill the pie chart’.

It’s a difficult life. I mean, who doesn’t like a good pie? It’s just that I have this image problem. People complain that I take up too much space on the page and I always bring a legend along to explain what I’m showing.

So, you’re struggling with your weight?

Well, it’s not really my fault. I like to stick to 3 or four slices maximum which is sensible, but people cram loads of slices into me which is not a good look. Apart from being confusing, I don’t have enough colours to keep track of all the slices, not only do I look half-baked, my fashion sense gets called into question too.

That doesn’t sound good.

And then they tell me to stand sideways for a 3d effect. It’s extremely embarrassing and my proportions look all wrong. And that’s before they want me to explode.  Why don’t these people understand that you can’t have your pie and eat it? Contorting into all these embarrassing positions to please everyone gives me a bad name, but when I’m used properly then I can be extremely helpful. I know that beauty is in the pie of the beholder, but there is a limit.

I feel your pain. So how can people make sure that you appear at your best?

I know that I take up a lot of space just to show a few numbers but it is ‘at a glance’ data communication so I think it’s a good use of space. Stick to three or four slices maximum, use clearly differentiated colours, try to avoid comparing similar numbers and I’ll be happy. Harvey Balls takes this to an extreme with only 1 colour and 1 number, but I’m more flexible than that, just please don’t take advantage of my easy-going nature.

I hear that you’re having a makeover nowadays.

Yes, you gotta roll with the times! Instead of pies you can have doughnuts, that’s a pie with a hole in the middle, that looks so much slimmer and svelte. The doughnut can be filled with an icon or a logo to show extra data.

And my best weight loss yet is the pie gauge. It’s just a single number, very snazzy looking and it doesn’t even need a legend.

The message I’m getting is that you’re all about showing as little data as possible? Like 3 or 4 numbers, or should I say 3.1415?

Very funny, I wondered how you would get that one in. Well, I definitely work best with showing just a few data points. If you need more, you can use a group of pies or try a different chart. I prefer not to be used than to be used badly. I should just mention that I’ve recently come up with the sunburst chart to show lots of data if you really want to do that.

Thanks. Some of our audience would like to know when’s the best time to start a pie.

14th March is international Pi day – no other chart has a whole day dedicated to them!  That’s a good date, what time though? Some people start at 12, others at 3, it’s never too early I think. I like to go clockwise. Negative numbers may go counter clockwise in a doughnut but I don’t really do negativity – I’m a positive type of guy.

So, to keep you positive and happy, what’s your advice to our audience?

Less is definitely more when it comes to pies.  Short, quick, and to the point.  Only a few points or your message will get lost in the clutter. And please, please don’t abuse me, you make me look silly.

Seems like we’ve come full circle, the life of a pie is difficult.

It is. Maybe someone will make a movie about it!