Bubbles – A Power BI Visualization
This week I am going to take another look at a custom visualization. This one is called Bubbles and is in some ways similar to last week’s look at the Word Cloud visualization. At least it looks similar in that the bubbles can appear as different colors, they are grouped together like the words were in a random pattern, and the size of the bubble, like the size of the text in the Word Cloud is a function of another numeric parameter. This time rather than the frequency of the word as in the Word Cloud, I can select any other numeric measure to define the relative size. In this case, I’ll use sales of the items within a product category and let each bubble represent one of the categories.
I’ll start by going to the Power BI Visualizations page found at: https://app.powerbi.com/visuals and click on the Bubbles tile. This displays the following dialog which tells me a little about the visualization including giving credit to its creator. Since I want to use this visualization, I next click on the Download Visual button.
While I will not show it here, there is an intermediate dialog that display the licensing terms for most visualizations. If you accept the license terms and proceed, your browser should download the visualization to one of your local folders. For me that is the Downloads folder. After it finishes downloading, I will move it to a folder where I keep other Power BI Visualization files.
Next I can open my desktop version of Power BI. In the background, I will load sales and product data from my Contoso sample dataset that I pften use and then switch to the Report page. On this page, I can click on the three ellipses at the bottom of the Visualizations group which is the Import from File button.
I will be shown a dialog which lets me locate the visualization file that I downloaded. Before loading the file, Power BI warns me about the perils of importing custom visualizations because they could contain code that could either circumvent the security on my computer or even access private information in my files. The fact that these files are hosted on a Microsoft site is not a guarantee of safety. However, they are more likely to be safe than other visualizations I may find elsewhere on the Internet.
After I start the import, I receive one more dialog when the process is complete.
The Bubble Visualization tile now appears in the bottom row of the Visualizations section. I’ve been asked whether I can rearrange the visualization tiles, perhaps alphabetically, by type or by some other factor. At this time, I have not discovered a way to do that so if someone has, please let me know. Of course the next update of Power BI may include that functionality so who knows.
Next I drag the fields I want to use into a blank area of the Report page. In this case, I want both the Sales Amount field and the Product Category Name. Initially, these data elements may display as a table or column chart (depending on which field you dragged into the report first). In either case, I can then click on the Bubble visualization and the character (text) field will be used to define the bubbles and the numeric field will be used to define the relative sizes of each bubble. The figure below the column chart version of the initial data added to the report page.
As I have shown before, to change the visualization, you only need to click on the tile in the Visualizations panel to change the currently selected visualization to another. Therefore, clicking on the new Bubble visualization results in the following:
If you hover over any of the bubbles with your mouse, Power BI shows the product category name value and the sales value for that category. Interestingly, because it was not what I expected, hovering anywhere outside the bubble but in the overall background (light grey here) displays the name and value of the largest bubble, not the total sales which is what I expected.
Like many other visualizations, you can click on any of the bubbles and that automatically filters any other visualizations on the page by the selected product category. I could also add a second table on the report page such as Calendar Year from the dimDate table and then define it as a Slicer. Then selecting different years in the slicer changes the Bubble visualization to represent data only for the year(s) selected.
The Bubble visualization has a few formatting options which I can get to by clicking on the pen (pencil) in the Visualization panel. I probably would like to see more options to control the colors of the bubbles which sometimes appear all the same color and sometimes as a few different colors. Perhaps if you too would like to see more control over the formatting of this or any other visualization, you should remember that the opening dialog from the Power BI Visualization download page provides a link to the author where you can send your thoughts and suggestions.
That’s it for this week. Next weekend is Christmas and then the week after is New Years. I will try to find time from celebrating to cover two other visualizations before getting back to some hard core data analysis next year.
C’ya next time.