public static PlotModel IntervalBarSeries()
        {
            var model = new PlotModel("IntervalBarSeries") { LegendPlacement = LegendPlacement.Outside };

            var s1 = new IntervalBarSeries { Title = "IntervalBarSeries 1" };
            s1.Items.Add(new IntervalBarItem { Start = 6, End = 8 });
            s1.Items.Add(new IntervalBarItem { Start = 4, End = 8 });
            s1.Items.Add(new IntervalBarItem { Start = 5, End = 11 });
            s1.Items.Add(new IntervalBarItem { Start = 4, End = 12 });
            model.Series.Add(s1);
            var s2 = new IntervalBarSeries { Title = "IntervalBarSeries 2" };
            s2.Items.Add(new IntervalBarItem { Start = 8, End = 9 });
            s2.Items.Add(new IntervalBarItem { Start = 8, End = 10 });
            s2.Items.Add(new IntervalBarItem { Start = 11, End = 12 });
            s2.Items.Add(new IntervalBarItem { Start = 12, End = 12.5 });
            model.Series.Add(s2);

            var categoryAxis = new CategoryAxis { Position = AxisPosition.Left };
            categoryAxis.Labels.Add("Activity A");
            categoryAxis.Labels.Add("Activity B");
            categoryAxis.Labels.Add("Activity C");
            categoryAxis.Labels.Add("Activity D");
            var valueAxis = new LinearAxis(AxisPosition.Bottom) { MinimumPadding = 0.1, MaximumPadding = 0.1 };
            model.Axes.Add(categoryAxis);
            model.Axes.Add(valueAxis);
            return model;
        }
        public static PlotModel GetErrorColumnSeries()
        {
            var model = new PlotModel("ErrorColumnSeries")
            {
                LegendPlacement = LegendPlacement.Outside,
                LegendPosition = LegendPosition.BottomCenter,
                LegendOrientation = LegendOrientation.Horizontal,
                LegendBorderThickness = 0
            };

            var s1 = new ErrorColumnSeries { Title = "Series 1", IsStacked = false, StrokeColor = OxyColors.Black, StrokeThickness = 1 };
            s1.Items.Add(new ErrorColumnItem { Value = 25, Error = 2 });
            s1.Items.Add(new ErrorColumnItem { Value = 137, Error = 25 });
            s1.Items.Add(new ErrorColumnItem { Value = 18, Error = 4 });
            s1.Items.Add(new ErrorColumnItem { Value = 40, Error = 29 });

            var s2 = new ErrorColumnSeries { Title = "Series 2", IsStacked = false, StrokeColor = OxyColors.Black, StrokeThickness = 1 };
            s2.Items.Add(new ErrorColumnItem { Value = 35, Error = 20 });
            s2.Items.Add(new ErrorColumnItem { Value = 17, Error = 7 });
            s2.Items.Add(new ErrorColumnItem { Value = 118, Error = 44 });
            s2.Items.Add(new ErrorColumnItem { Value = 49, Error = 29 });

            var categoryAxis = new CategoryAxis { Position = AxisPosition.Bottom };
            categoryAxis.Labels.Add("Category A");
            categoryAxis.Labels.Add("Category B");
            categoryAxis.Labels.Add("Category C");
            categoryAxis.Labels.Add("Category D");

            var valueAxis = new LinearAxis(AxisPosition.Left) { MinimumPadding = 0, MaximumPadding = 0.06, AbsoluteMinimum = 0 };
            model.Series.Add(s1);
            model.Series.Add(s2);
            model.Axes.Add(categoryAxis);
            model.Axes.Add(valueAxis);

            return model;
        }