R Or M?

Kevin Feasel

2016-08-17

Power BI, R

Ryan Wade gives a few scenarios in which R might be a better language choice than M for Power BI integration:

When referring to what can be done in iOS, Apple often say that there is an “app” for that. Likewise, when R developers refer to what can be done in R, we often say that there is a “package” for that. For instance:

· If one needs to scrap data from the web there are packages for that (rvest, rcurl, and others)

· If one needs to make complicated transformations to their data there are packages for that (dplyr, tidyr, lubrdiate, stringr, and others)

I like the F#-ness of M, but I admit that I’m happy there’s some fairly close R integration within Power BI, as that means there’s one fewer language I need to learn right now…

Power BI Storage Regions

Adam Saxton explains where Power BI stores your data and how they choose the region:

This selection is what drives the location of where your data will be stored. Power BI will pick a data region closest to this selection. This selection CANNOT BE CHANGED! You will want to think about the location that makes the most sense for you.

For example, if the majority of your organization’s users are in Australia, and you are in the United States, it probably makes more sense to select Australia for the country. You may also have legal requirements that your organization’s data needs to be in a specific country.

The “cannot be changed” part means that this decision is a lot more important than you might first realize.

Power BI DirectQuery

Adam Aspin explains some of the concepts behind DirectQuery:

In this article I will not be looking at Power BI as a data visualization tool. Indeed, I will not be discussing in anything more than a cursory way the data transformation and modelling capabilities of this product. Instead, I would like to focus on using Power BI Desktop to connect directly to certain data sources. So although you need no previous knowledge of Power BI Desktop to understand this article, I will be providing only an extremely succinct glance at the extensive array of the data mashup and modelling techniques that are available. Nor will I be explaining any of the approaches that can be taken to create visuals and dashboards. I will, however, try out a few classic techniques using the Power BI Query Editor and Data Model to see if there are any limits to using DirectQuery when compared to data loaded into the in-memory model. The aim here is to see just how, and in what circumstances, DirectQuery can help you to analyze your data faster and more easily.

This article is lengthy but good.  Check it out.

Power BI Calendar Visualization

Devin Knight continues his Power BI visualization series and looks at a custom calendar visual:

  • Allows you to visualize a data point on each date on the calendar.

    • The darker the color, the higher the value or density of values.
  • If you have multiple rows on the same date they are aggregated together

  • The Calendar Visualization can be used for cross filtering. Meaning you can select a square in the calendar and it will filter other visuals down to the date you picked.

This is an interesting visual.  It’s dense, but not difficult to understand.

Trapping HTTP Error Codes In Power BI

Chris Webb shows how to handle specific HTTP error codes when using the Web.Contents() function in M:

This thread on the Power Query forum suggests it’s something to do with lazy evaluation, but I haven’t been able to determine the situations when it does work and when it doesn’t.

Instead, it is possible to handle specific HTTP error codes using the ManualStatusHandling option in Web.Contents()

I guess this beats not being able to handle errors at all, but it seems like a fairly fragile solution if you next want to start handling the entire 500 class of response codes.

Power BI Embedded

Reza Rad looks at Power BI Embedded:

Power BI Embedded is the reporting and analysis solution for mobile and web applications. Power BI Embedded is an Azure service that integrates Power BI solution into mobile and web applications. The report still has to be authored and created in Power BI Desktop. After creating the report it can be published into Power BI workspace in Azure, and using API Keys of Power BI workspace and embedding Power BI report frame into the web/mobile application it will be integrated into the application.

Reza walks through the process step-by-step.  The upshot is that you can take this report you created in Power BI and embed it into your own application, where you can apply your own in-app access controls.  There are limitations, which Reza spells out at the end of the post, so check it out.

Managing Power BI Group Workspace Members

Melissa Coates shows how to mange Power BI groups with larger numbers of members:

Dozens or hundreds of users in a group is what is prompting me to write this post. Manually managing the members within the Power BI workspace is just fine for groups with a very small number of members – for instance, your team of 8 people can be managed easily. However, there are concerns with managing members of a large group for the following reasons:

  • Manual Maintenance. The additional administrative effort of managing a high number of users is a concern.
  • Risk of Error. Let’s say there is an Active Directory (A/D) group that already exists with all salespersons add to the group. System admins are quite accustomed to centrally managing user permissions via A/D groups. Errors and inconsistencies will undoubtedly result when changes in A/D are coordinated with other applications, but not replicated to the Power BI Group.Depending on how sensitive the data is, your auditors will also be unhappy.

To avoid the above two main concerns, I came up with an idea. It didn’t work unfortunately, but I’m sharing what I learned with you anyway to save you some time.

Even though Melissa’s plan didn’t work, it’s a good concept, so I recommend reading.

Card With States Visualization

Devin Knight looks at the Card with States Power BI custom visual:

Key Takeaways

  • Allows you to bind performance measures to 3 states.

    • The thresholds for these 3 stages can be set manually or be data driven.

  • It can visualize one measure while using a different one for the indicator value

This is a pretty small visualization, but it could be useful as part of a larger dashboard.

Scatter Charts

Reza Rad shows how to use a scatter chart in Power BI:

Scatter chart is a built-in chart in Power BI that you can show up to three measure with a categorization in it. Three measures can be visualized in position of X axis, Y axis, and size of bubbles for scatter chart. You can also set up a date field in play axis, and then scatter chart will animate how measure values are compared to each other in each point of a time. Let’s start building something simple with this chart and see how it is working in action. At the end of example you will see a summary chart as below;

This is primarily for viewing changes in groups of data over time.  You don’t want too many data points on the map or it gets too confusing.

Traversing DAX Hierarchies

Meagan Longoria shows how to implement hierarchical slicing and filtering using DAX:

My friend and coworker Melissa Coates (aka @sqlchick) messaged me the other day to see if I could help with a DAX formula. She had a Power BI dashboard in which she needed a very particular interaction to occur. She had slicers for geographic attributes such as Region and Territory, in addition to a chart that showed the percent of the regional total that each product type represented.  The product type was in the fact/data table. Region and territory were in a dimension/lookup table and formed a hierarchy where a region was made up of one or more territories and each territory had only one region.

It’s rare to hear me say “MDX was easier” but in this case, MDX was easier…

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