An Idea For Using Index in Power BI

Just trying to chill out. The news is frightening.

So today I will be writing about something on the lighter end – I’ll just touch on an idea I had when I was trying to compare two sets of data that ran over a period of time. But these data sets began on different dates and sometimes that time difference can make it difficult to compare the two data sets.

Here’s an example of data set A and B whose measurements were taken over a period of time. Data set B began at a later data and in this case, it looks very similar to data set A but I wanted to be sure.

Then I had an idea: I thought “what does Index, found under the Add Column tab in Power BI, do”? I tried it out and found that index numbered each data point with a sequential number, starting with zero. Rather than use dates, I can use the index numbers to plot the data sets. First, I had to find a good starting point, one where each data set has. In my set of data, data set A had 41 and data set B had 42 – practically the same. Once I found the initial starting point to plot, next I had to delete some data rows to reach the 41 or 42 to make those numbers the starting point. Then I added an index column and both 41 and 42 had an index of zero.

Here’s the result. In this graph, it looks like data set B started slow but then appears to be accelerating faster. That just might be enough of a difference to come up with a different interpretation. Now there is a problem in data set B where there are missing data on certain dates, so that has to be kept in mind when making interpretations. It may be that B is really not accelerating faster.