Pie Chart is bad!

Pie Chart is bad!

      During my presentation at Power Saturday in Paris, I wanted to demonstrate to an already very optimistic public that Power BI is a great tool and that modeling is a must-have for their reports. (Data Modelling is not the subject here)
Power BI a super tool? Yes, and to complete this idea, I added some slides to highlight each piece of the tool.

One of the slides showed the ease and elegance of the visuals.
After a quick search on Google images, I copied a screenshot created by a user in Power BI and added it to my presentation.

In the audience, two friends looked at me with a horrible face. The damage was done, I had slipped the image of a Pie Chart!

Nothing crazy, isn’t it? But when you know a bit of the history of the Pie Chart, we realize that this visual component is not recommended in the world of Data Viz. This blog post also follows some more or less tense discussions between colleagues.

I wrote this article for many reasons:

  • This point is already super documented on internet, but some people never read them before. (I provide links at the end)
  • I wanted to convinced myself first, and created a Power BI file to confirm this point. (CFR the following screenshot)

I was a Pie Chart lover

I know that its use is not recommended and I try not to use it.
But yes, I liked it!
• It’s beautiful!
• It’s colorful!
It gives a professional look to our reports!
• It shows information!
It gives me some pride to not use tables or matrix. (Yes, I like numbers, not you?)

I think we are used to seeing this kind of visualization since our earliest childhood in commercial brochures, professional documents.

The Pie Chart is visual, and help us to return informations quickly. But unfortunately, this information is not always the right one.


To compare groups, we evaluate the difference of the amplitude of the angles while a histogram will request us to compare lengths between them.

A long description is not needed, I would prefer to show you 2 set of data, both represented in a Pie Chart and histogram.

Your first look will give you some information, but not as much precise compared to the two histograms below. It’s possible to have quick information, but very hard to have a clear interpretation of them.

If I didn’t convince you, try to sort each portion from the smallest to the biggest. Try to do the same with the histogram and compare the time elapsed for both.

PowerBI – Bookmarks

PowerBI – Bookmarks

Bookmarks are not perfect, I can easily confirm you. But with them, you can build beautiful and rich reports.

In this example, I will show you how your users can switch from one visual to another one.

Update Power BI Desktop : More information with less visuals ? Let’s use the Tooltip !

Update Power BI Desktop : More information with less visuals ? Let’s use the Tooltip !

*This post is an update to the video about the Tooltip*

It can be sometimes very difficult to put all the information we need in only one report page. Maybe I could remove this visual to add this one instead? But then, I won’t have the figures for this year. Maybe this one then? Impossible, otherwise I’ll miss the ranking of my product. It can easily become a real headache.

What if there was a wonderful feature inside Power BI Desktop allowing us to add more visuals to our report within the same space… Stop dreaming, I have a good news for you, it exist! Well, kind of. The tooltip will give you the opportunity to add a visual when you hover a cell of another visual. Still a bit confused? Let’s see how to do it and the final result.

As always, let’s first take the LazyDAX file (such a masterpiece I know). We can create a new page and add a new visual in it. Here is our “test” page with a simple Cost by Customer and by Year table.

Nothing complicated until there. By default, when you hover a cell of this report, you will only have a small definition of the cell, or maybe a quick resume of the whole line. Ok, why not but it’s not that interesting.

What we would like to have instead is something more relevant, more useful to the business and the end user, something more visual. Perfect, the tooltip is made for this. Let’s create a new blank page. It will be our tooltip page.

Now we can go on the format pane of the page. Under the “Page Information” tab, we will set “Tooltip” on “On”. That way, the page will be considered by Power BI as a tooltip

Now you can also go on the “Page Size” tab and choose the “Tooltip” type. You don’t have to do it but it’s better to keep something visually harmonious.

Now you can create the report that will be displayed as a tooltip to your report.  Let’s take something like the Cost by Product.

Here is the report with the tooltip format. Ok it gives more information but it’s not really readable. Don’t worry, just wait and see how the magic happens.

But first we have to go back to our report page and select the visual that will have the Cost by Product report as tooltip. Select the visual.

Go on the “Format” tab and enable “Tooltip”. Once it’s done, under “Type” you select “Report page” (the way you will see the tooltip) and then select “Tooltip Page” (the source page with your tooltip).

Now we can see the magic. When I hover one cell of my table, I will have the report of the “Tooltip Page” displayed and sorted by the current line.

This is a really simple way to add more information without overloading your page.

Once again, it was not something very difficult, you just had to be aware of it.

Power BI Desktop: Print in the A4 size

Power BI Desktop: Print in the A4 size

As you know, the August 2018 update of Power BI Desktop grants us the possibility to export in PDF directly from the Desktop. Two clicks and it’s done. Great news right? I remember all the steps I had to go through to make it before, it still give me headache…

But by default, the report will be exported with the standard format of Power BI Desktop which can be for some end users or clients not very pleasant to read especially if they are used to an A4 page. The real question is then, how to export in that specific format? Here is the answer.

First, let’s take our wonderful LazyDAX file and create a new page. Here is the default view you have when adding a new page.

Nothing special until there. What’s interesting is the “Page View” button under the “View” tab. Once we click on it, we can select “Actual Size”.

By choosing “Actual Size” we will see the “real” size of the page, based on its dimensions.

Now we can see that the page size exceed the usual limit of the report. But we want to make it like a A4 portrait page right? So, we are not done yet. You can select the “Format” pane of the report page, then “Page Size” and select “Custom” as “Type”.  Now, we just have to enter the custom size we want. I chose 794*1123 pixels because it is the A4 size at 96 PPI (depending of the printing, you can find more info about it here).

Now we have our A4 report page ready to be filled.

As you can see, there is now a scroll bar on the right side of the report because of the dimension of the page. We now just have to export as PDF and that’s it. You can click on the “File” button and then choose “Export to PDF”.

You now just have to let Power BI make the work and here is the result.

The last report page is well in portrait format, while the others have been exported in the default format.

As you can see, there is nothing really difficult here but you just have to be aware of it.