In this post, I describe how to write an optimized median measure in Dax which under specific criteria can be 1,000 times faster than the built-in median function.Some time ago I was tasked to migrate a multidimensional cube to a tabular model, this cube had around 2 billion rows and I also had to create a median measure on the new tabular model. I first thought that the median would be much faster to calculate on a tabular model than on…
In this post, I will describe how we can implement a paired t-test in Power BI using DAX only. What is T-Test A t-test is a type of inferential statistic that can be used to determine if the means of two groups of data are significantly different from each other. In other words, it tells us if the differences in means could have happened by chance. There are three types of t-test: An Independent Samples t-test compares the means for two groups. A Paired sample t-test compares means from…
In this small post, I’m sharing and will keep up to date the list of the most common univariate statistics DAX functions available in Power BI, as of now most of them are built-in functions but the more complex ones still require writing some Dax code. I’m sharing this through a Power Bi app where we can simply copy/paste the DAX code of the selected function. The Power BI
In this post, I will describe what is the Pearson correlation coefficient and how to implement it in Power BI using DAX. What is the Correlation Coefficient The correlation coefficient is a statistical measure of the relationship between two variables; the values range between -1 and 1. A correlation of -1 shows a perfect negative correlation, and a correlation of 1 shows a perfect positive correlation. A correlation of 0.0 shows no linear relationship between the movement of the two variables. How…
In this post, I will describe what Skewness and Kurtosis are, where to use them and how to write their formula in DAX. What is Skewness Skewness is a measure of symmetry, or more precisely, the lack of symmetry. A distribution, or data set, is symmetric if it looks the same to the left and right of the centre point. For a unimodal (one mode only) distribution, negative skew commonly indicates that the tail is on the left side of the distribution, and positive skew…
In this post, I share how to perform a bootstrap analysis with Power BI and briefly introduce what is bootstrapping and when to use it.
A/B testing, or split testing, is a digital marketing technique that involves comparing two versions of a web page or application to see which performs better.
In this post, I am going to share a step by step guide to implement AB Testing with Power BI.
Now it’s been a year since the game-changer new calculation groups feature has been released and I just thought that I still haven’t written a post on it. Goals of this Post Use Calculation Groups Use Tabular Editor Advanced Scripting Speed up SSAS/PowerBI model development Create reusbale script Setting up the Environment Power BI: Download here. Tabular Editor: Download here. SQL Server 2019 and later Analysis Services or Azure Analysis Services. At the time of writing this post, Calculation Group…
I’ve previously written an article on how to dynamically convert and change the currency of a measure using a slicer.Now let’s see how we can use dynamic format strings for currency conversion in PowerBi with DAX. Model Prerequisite Add the FormatString column into your currency dimension You can download the file with the sample format string from here.Make sure to use a Unicode type column to store the different format strings otherwise the collation of your DB might not support…
Treatas is a powerful DAX function that applies the result of a table expression as filters to columns from an unrelated table. In other words, treatas applies the filter context of a specific table to another unrelated table (no relationship in the model). Book to Bill ratio A book-to-bill ratio is the ratio of orders received vs orders shipped and billed for a specific period, a month in our case. The book-to-bill ratio reveals how quickly a business fulfils the demand for…
In Power BI the slicers allow us to filter and view only the information that we want but we can also in Power BI Exclude data based on Slicer selection. In this short post, I will show how we can reverse the behaviour of a slicer “excluding” the selected values instead of “filtering” the selected values. What is a Power BI Slicer? In Power BI a Slicer is a canvas visual that allows us user to filter and view only…
Since the latest Power BI release (June 2019) we are now able to filter a slicer based on a measure!And I think we’ve all been waiting for this feature for quite a while. One of the top reason we needed this feature was to have the ability to sync slicers. (Well this was already achievable with the bidirectionnel filter which is a really bad practice…) So as we can see on the example below the customer Alma has bought only…
In this post, I illustrate how to implement Deviation From Average in Power BI and why we should use it. Margin is a key metric to assess high-level performance of a company. But sometimes we want to measure and compare specific shop or department or employee performance with the entire company overall performance and this where deviation from average metric comes to help. The requirement are as follows: Company overall margin over time (which is just the margin average) Employee…
Let’s assume a scenario where we have 50 time intelligent measures and 5 dimension Dates (order, invoice, ship, due, calendar…). If we want the 50 measure to interact with the 5 dimensions we would need to create 250 measures which might rapidly overwhelm the users as they must sift though so many measures. This script below allows you to drag any dates with the YTD margin measure and the measure will dynamically apply the calculation accordingly and thus keeps our…