#2879 Different arrow heads with the same parameters

[Anonymous]

Environment:
gnuplot 6.0 patchlevel 4
Ubuntu 24.04.4 LTS (x86_64)
Reproduced with both pdf and pdfcairo terminals. The behavior is reproduced with gnuplot 6.0.0 and 6.0.4

Observed behavior:
The attached script produces two sets of arrows. Although all arrows use the same arrowhead specification, some are rendered with pointed tips whereas others have flat/blunt tips. I have not been able to determine whether this is intended behavior or a rendering bug.

Expected behavior

Arrowheads with identical specifications should have identical geometry, independent of the length (provided the specified arrow is not shorter than head length).

[Ethan Merritt]

This script later attached to tracker 2880 does not reproduce the PDF output attached here. The size and aspect ratio are different, and the resulting plot is so small that the arrows form one large blob.

I will hazard a guess that what you are seeing is that the linewidth is so large compared to the arrowhead that (1) the border drawn around the arrowhead deforms the shape and/or (2) the front end of the arrow shaft extends out all the way to the tip of the arrow head and maybe beyond so it occludes the head.

(1) can be fixed by using the attribute "noborder" for the arrow style rather than "filled"
(2) can be ameliorated by making sure the line-end style is "butt" rather than "square" or "rounded". This should already be the default but I suppose it is possible that your local gnuplot changed the default somewhere?

You probably want a thinner line width. Note that the linewidth given in a plot command is multiplied by the global linewidth scale from "set term", so your arrows are really using a line that is nine times the default.

set term pdf linewidth 1 butt  size ??,??
...
set arrow 151 ... noborder lw 3 lc rgb "#FF3333"