Rogue lines in colorfill plot

[jclarkeSTFC]

Original reporter: James Lord

Describe the bug Original email: This seems to have been around for a version or three but is still there in the beta nightly 6.8.20240202.1625 (Windows):

Load a data set with a lot of zeros in it and a few high valued bins (e.g. HIFI run 185451, which is dark counts and with the DAE not working properly so some spectra are completely empty)

Plot – Colour Fill. There should be some coloured in pixels with most of the graph dark blue/black (zero). But there may be a yellow horizontal line for example (narrower than one spectrum along that axis).

Resize the plot window with the mouse, and the line may change colour, change to dotted/dashed, or be accompanied by more horizontal and vertical lines.

The effect doesn’t show up if I load “normal” muon data with non-zero counts in most bins.

James

To Reproduce

• Load HIFI 185451
• Open colorfill plot
• Drag bottom right corner around to resize, random horizontal and/or vertical lines will appear in the plot.

Expected behavior

• No random lines

Screenshots

Platform/Version (please complete the following information):

• OS: Windows
• OS Version: 10
• Mantid Version 6.8 (but present in earlier versions)

[GuiMacielPereira]

I couldn't find the reason for why this is happening, but I did notice that simply updating the plot settings makes these lines go away

[jhaigh0]

If we can't firgure this out, should we make sure James Lord knowns about the workaround you've figured out?

[GuiMacielPereira]

I have contacted James to let him know

[jclarkeSTFC]

This happens with matplotlib 3.8 as well