powerbidaxpowerbi-desktopvega-litedeneb

Why line chart doesn't plot measures that have same value for X-axis in Power BI?

I have the following data in Power BI.

X | Y

10 | 2

11 | 3

12 | 4

13 | 5

14 | 6

15 | 7

15 | 10

Both X and Y were set to Don't Summarize.

Then I created a measure for Y as follows:

newY = SELECTEDVALUE(Sheet6[Y])

The reason for the measure is that I don't want to do any calculation (sum, count...) when creating the line chart.

Just want to plot the values on the chart.

So using the solution proposed here: How to create a basic line chart in Power BI?

Then created a line chart dragging X to the x-axis and newY to the Y-axis in the Visualizations pane.

This is the resulting chart:

enter image description here

Question is:

Why didn't it plot (15, 7) and (15, 10) continuing the line until there?

I would like them plotted and have the result be like this:

enter image description here

Solution

  • This is just the way PowerBI and DAX works. SELECTEDVALUE() returns a single value only if a single value is in the context. At x = 15, you have two values in context (7 and 10) hence SELECTEDVALUE() will return blank. I know you're frustrated that PowerBI can't operate the same as Excel but the native line chart is a bit limited and I know the team are working on updates to it. You can still do what you want in Power BI but you will need to use Deneb.

    For example, here is a Deneb line chart which does what you like:

    enter image description here

    Created with this code (Vega-Lite) which you put into Deneb.

    {
  "$schema": "https://vega.github.io/schema/vega-lite/v5.json",
  "data": {
    "values": [
      {"X": 10, "Y": 2},
      {"X": 11, "Y": 3},
      {"X": 12, "Y": 4},
      {"X": 13, "Y": 5},
      {"X": 14, "Y": 6},
      {"X": 15, "Y": 7},
      {"X": 15, "Y": 10}
    ]
  },
  "mark": "line",
  "encoding": {
    "x": {"field": "X", "type": "quantitative"},
    "y": {"field": "Y", "type": "quantitative"}
  }
}