/// <summary>
/// Zooms at the specified position.
/// </summary>
/// <param name="axis">
/// The axis.
/// </param>
/// <param name="factor">
/// The zoom factor.
/// </param>
/// <param name="x">
/// The position to zoom at.
/// </param>
public void ZoomAt(Axes.Axis axis, double factor, double x = double.NaN)
{
if (double.IsNaN(x))
{
double sx = (axis.Transform(axis.ActualMaximum) + axis.Transform(axis.ActualMinimum)) * 0.5;
x = axis.InverseTransform(sx);
}
axis.ZoomAt(factor, x);
}