Trend line over multiple scatter plots

I have data and a graph made from that data as such:

I would like to have best fit curves/lines for each of the tests in the graphs. When I double click on the chart and hit insert, the trend line is disabled.


This is the file am trying to get to work. Specifically it is the last sheet “Summary of all tests”

Could you share test file without any personal or sensitive info (check File → Properties) so that it’s not needed to recreate data and graph from scratch just for sake of checking what might be wrong? Thanks

@Kruno, I added the file I an trying to get to work. There is no sensitive info, just data that is dumped from the program, its the program that generates the data that I cannot share, I see no harm in sharing this.

I think the problem is the way you are trying to do it. The ‘add trendline’ entry on the insert menu is probably greyed out because there are multiple data series and the program wouldn’t know which to use. Instead, after you select the chart, if you right-click on one of the data points, the context menu includes an option to add a trend line for that data series.

An interesting note: when one does this in Excel, the trendiness all default to black, making it difficult to know which data series they belong to. In LO Calc, the trendlines default to colours that match the existing data series. (OSX 10.11.6, LO 6.0.2, Excel 2011).

You are absolutely right. I needed to select a point for it to work for that data series, I assumed it should do it for all of them separately.

Your Brute Force graph has six data series. You can insert a trend line for each series individually. But your X ranges for each series do not match the Y ranges and this distorts the graph.

If you want a single trend line covering all the data, set up a single data series with all graph size values (x values) in column b and all runtime values (y values) in column c, then do a graph.