Weird vertical lines with plot function

Dear all,

While trying to plot a specific dataset, I encouter a weird behavior:

load elpenon
figure; scatter(elpenon(:,1)*1000,elpenon(:,3),10,'k')

gives the appropriate plot

However, when calling :

figure; plot(elpenon(:,1)*1000,elpenon(:,3))

Warning: Graphics acceleration hardware is unavailable. Graphics quality and performance might be diminished. See MATLAB System Requirements.

I obtain this :

These weird vertical lines appears. No data support this as shown in the scatter plot.

max(elpenon(:,3))=-1.3800

so nothing above 0 but stil shown in the plot

changing linejoin properties does not solve the issue. The plot although is correct when setting linewidth to .1.

When using the pan tool in the figure window to move the plot around, the vertical lines diseappear when the origin of the extra line is outside of the x and y lims.

Can anyone explain this and propose a workaround?

Thanks

[Stephen23]

What OS ?

version

ans = '26.1.0.3203278 (R2026a)'

S = load('elpenon.mat')

S = struct with fields:
    elpenon: [3594×3 double]

M = S.elpenon

M = 3594×3

12.0700 0 -4.5500 12.1100 0.4000 -3.5100 12.1600 0.8000 -4.0400 12.2000 1.2000 -4.6700 12.2500 1.6000 -4.9600 12.2900 2.0000 -5.3800 12.3400 2.4000 -5.0600 12.3800 2.8000 -5.3200 12.4300 3.2000 -5.3900 12.5200 4.0000 -5.3000 12.5600 4.4000 -5.1700 12.6100 4.8000 -5.3100 12.6500 5.2000 -5.5400 12.7000 5.6000 -5.4400 12.7400 6.0000 -5.6800

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scatter(M(:,1)*1000,M(:,3),10,'k')

plot(M(:,1)*1000,M(:,3))

[Olivier]

Dear Stephen23

MacOS Tahoe V 26.4.1

[Walter Roberson]

Datapoint:

I obtain normal plots with R2025b on MacOS Intel Tahoe 26.5

Answer 1

[Star Strider]

I am unable to reproduce that here.

This appears to produce the expected result --

LD = load(' elpenon.mat')

LD = struct with fields:
    elpenon: [3594×3 double]

elpenon = LD.elpenon;

figure
plot(elpenon)
grid
legend(compose('Column #%d', 1:size(elpenon,2)), Location='best')

figure
plot(elpenon(:,1)*1E+3, elpenon(:,3))
grid

.