In Chart.withLegendStyle, StyleParam.XAnchorPosition does not seem to have an effect

[nhirschey]

Description

When I try to orient a legend, YAnchorPosition works as I expect but XAnchorPosition does not seem to have an effect.

Repro steps

#r "nuget: Plotly.NET"

open Plotly.NET

let xs = [1.0 .. 4]
let y1 = xs |> List.map (fun x -> x * 2.0)
let y2 = xs |> List.map (fun x -> x * 3.0)

These charts look the same to me:

// left
[Chart.Line (xs, y1); Chart.Line (xs, y2)]
|> Chart.combine
|> Chart.withTitle("Left")
|> Chart.withLegendStyle(Orientation=StyleParam.Orientation.Horizontal,
                         X=0,
                         XAnchor=StyleParam.XAnchorPosition.Left)
|> Chart.show

// right
[Chart.Line (xs, y1); Chart.Line (xs, y2)]
|> Chart.combine
|> Chart.withTitle("Right")
|> Chart.withLegendStyle(Orientation=StyleParam.Orientation.Horizontal,
                         X=0,
                         XAnchor=StyleParam.XAnchorPosition.Right)
|> Chart.show

Expected behavior

I expect the left chart to be as it is but I expect the right chart's legend to be right-aligned at x=0.

Actual behavior

the legend positions are the same.

Related information

• Operating system Windows 11
• .NET 6,

[kMutagene]

This seems to be intended. See the plotly.js docs :

Sets the legend's horizontal position anchor. This anchor binds the x position to the "left", "center" or "right" of the legend. Value "auto" anchors legends to the right for x values greater than or equal to 2/3, anchors legends to the left for x values less than or equal to 1/3 and anchors legends with respect to their center otherwise.

Seems like you have to controll the position additionally via increasing X:

Type: number between or equal to -2 and 3
Sets the x position (in normalized coordinates) of the legend. Defaults to "1.02" for vertical legends and defaults to "0" for horizontal legends.

so a combination of X = 1 and XAnchor = "right" should work.

[Chart.Line (xs, y1); Chart.Line (xs, y2)]
|> Chart.combine
|> Chart.withTitle("Left")
|> Chart.withLegendStyle(Orientation=StyleParam.Orientation.Horizontal,
                         X=1,
                         XAnchor=StyleParam.XAnchorPosition.Right)
|> Chart.show

However, this will lead to this result, because XAnchor falsely set the YAnchor attribute currently >.<

I patched this already and this will be live with the next release.

[nhirschey]

That looks great, thank you! Good eye catching the typo causing the bug; that would be hard to catch.