OxyPlot: How to use the axis label formater and sh

I'm using to Oxyplot for my Xamarin.iOS project for plotting a bar chart..

This is what my graph currently looks likes currently

here's instead of x axis values which are numbers, I want to show sun, mon true, wed.....

I can see that CategoryAxis has a method called LabelFormatter which returns Func<double, string>, but how do I use it?

And also why are the Y-Axis labels not showing???

public class MyClass
    {
        /// <summary>
        /// Gets or sets the plot model that is shown in the demo apps.
        /// </summary>
        /// <value>My model.</value>
        public PlotModel MyModel { get; set; }

        /// <summary>
        /// Initializes a new instance of the <see cref="OxyPlotSample.MyClass"/> class.
        /// </summary>
        public MyClass()
        {

            var model = new PlotModel { Title = "ColumnSeries" };
            model.PlotAreaBorderColor = OxyColors.Transparent;
            // A ColumnSeries requires a CategoryAxis on the x-axis.

            model.Axes.Add(new CategoryAxis()
            {
                Position = AxisPosition.Bottom,
                MinorTickSize = 0,
                MajorTickSize = 0,
                //MajorGridlineStyle = LineStyle.Solid,
                //MinorGridlineStyle = LineStyle.Solid,
            });

            model.Axes.Add(new LinearAxis()
            {
                AxislineStyle = LineStyle.None,
                Position = AxisPosition.Left,
                MinorTickSize = 0,
                MajorTickSize = 0,
                MajorGridlineStyle = LineStyle.Solid,
                MinorGridlineStyle = LineStyle.Solid,
                Minimum = 0,
                Maximum = 400,
            });

            var series = new ColumnSeries();
            series.Items.Add(new ColumnItem() { Value = 200, Color = OxyColors.Orange});
            series.Items.Add(new ColumnItem(200));
            series.Items.Add(new ColumnItem(300));
            series.Items.Add(new ColumnItem(100));
            series.Items.Add(new ColumnItem(200));
            series.Items.Add(new ColumnItem(100));
            series.Items.Add(new ColumnItem(130));

            model.Series.Add(series);

            this.MyModel = model;
        }
    }

To show the label on the axis you have to specify the property MajorStep, Oxyplot will paint only the labels matching the major step.

model.Axes.Add(new LinearAxis()
{
    MajorStep = 10,
    Position = AxisPosition.Left,
    ...
});

And to modify the labels with the day name, you can use a DateTimeAxis instead of LinearAxis:

model.Axes.Add(new DateTimeAxis()
{
    StringFormat = "ddd",
    Position = AxisPosition.Bottom,
    ...
});

If you want something more customized you will have to use the LabelFormatter attribute.

EDIT:

Labels in CategoryAxis:

var categoryAxis = new CategoryAxis()
{
    Position = AxisPosition.Bottom,
    ...
};

categoryAxis.ActualLabels.Add("Mon");
categoryAxis.ActualLabels.Add("Tue");
categoryAxis.ActualLabels.Add("Wed");
categoryAxis.ActualLabels.Add("Thu");
categoryAxis.ActualLabels.Add("Fri");
categoryAxis.ActualLabels.Add("Sat");
categoryAxis.ActualLabels.Add("Sun");

Model.Axes.Add(categoryAxis);

CategoryAxis.ActualLabels is readOnly, so you will have to Add the items one by one.