NCartesianChart chart1 = new NCartesianChart();
nChartControl.Charts.Add(chart1);
NPolarChart chart2 = new NPolarChart();
nChartControl.Charts.Add(chart2);

...

// I know how to do this
NVector2DD ViewToCartesianScale(in MouseEventArgs e)
{
    NViewToScale2DTransformation view2Scale =
        new NViewToScale2DTransformation(chart1,
        (int)StandardAxis.PrimaryX, (int)StandardAxis.PrimaryY);
    NVector2DD cartesianCoord = new NVector2DD();
    view2Scale.Transform(new NPointF(e.X, e.Y), ref cartesianCoord);
    return cartesianCoord;
}

// I want to know
void ViewToPolarScale(in MouseEventArgs e, out double angle, out double radius)
{
    ??
}