Specify different pivot for arrow marker type?

📊 Plotly Python
1

I cannot find anything in the documentation regarding this. When using the arrow marker symbol in combination with the angle option it seems that the arrows are pivoted around the tip of the arrow. For me this is a problem because I’m trying to align the errors onto a line, as shown in the figure.

newplot
newplot1260×143 12.2 KB

Is there any way to pivot the arrows around the center and not the tip?

The code to produce this is really simple

    fig.add_trace(
        go.Scatter(
            x=data["time"] 
            y=[0.5] * len(data["time"]),
            mode="markers",
            marker=dict(
                size=12,
                color="DarkSlateGrey",
                symbol="arrow",
                angle=data['wind_direction_10m_dominant'] - 180.0,
            ),
        ),
    )
2

Hi @guidocioni ,

Instead of using symbol="arrow", maybe you can try use symbol="triangle-up" .
The triangle will be pivoted around center of the triangle not the tip.

3

Unfortunately all the triangles symbols do not really show clearly a direction because they are symmetric :frowning:

Screenshot 2024-08-29 at 10.02.27

To be honest I don’t understand why almost all symbols, besides the arrows, are pivoted to the center…

4

I also found that annoying.
It would be really nice to allow the pivot for the arrow to be selectable, or have a arrow-center option.

The Triangle is too symmetrical and all the “arrow” style variants have the tip pivot. It’s great that it’s possible to pivot based on the tip but removing the ability to pivot around the center makes it look weird on some apps.