my problem is the following (didn't find info how to do it in the official documentation) - recorded ~108k ping results to LibreOffice table with columns
- DATE (letter A),
- LATENCY (letter B),
- STATUS (letter C).
Some rows contain empty cells for LATENCY (requests timed out for echoes waited 3000ms or more), that's why I managed to mark them with RED background color in Conditional formatting and then created an "Area" type chart with date/latency as X/Y values.
How to edit the chart so those empty cells are shown as RED vertical lines (3000ms long RED lines) in the same chart? You can see the current chart in the attached image.