Function plot_contour 

pub fn plot_contour<T>(
    data: &ArrayBase<ViewRepr<&T>, Dim<[usize; 2]>>,
    num_levels: usize,
    config: &PlotConfig,
) -> Result<String, NdimageError>
where
    T: Float + FromPrimitive + ToPrimitive + Debug + Clone,

Generate a contour plot representation of a 2D array