seriesDashStyle

Specifies the line draw style. Possible values are:

Solid
ShortDash
ShortDot
ShortDashDot
ShortDashDotDot
Dot
Dash
LongDash
DashDot
LongDashDot
LongDashDotDot

Default is Solid.

seriesSettings: {
    polarline: {
        seriesDashStyle: "ShortDashDotDot"
    }
}

This setting is demonstrated in the following example.