OxyPlot BarSeries shows white screen

Question

Creating a script using C# and the OxyPlot class. The script will learn to tell the difference between a sunflower image and a dandelion image.

The problem I have is the PlotView of the PlotModel, which I added a Barseries to, does not show any data/bar lines. It does show a PlotView screen but it is empty. Just a white screen . with no axis lines, and I do not know how to fault find where the issue is. I think it has to do with how I am calling the PlotView.

Complete white screen with no data suggests that I am NOT calling the correct form.

I looked at the BarSeries variable and confirmed that is has 100 items attached. The properties with this data is 'Color', which has an oxyPlot color value, 'Value' which has a percentage value as a double datatype (range for this is from 0.0 to a highest of 2.5) and a 'CategoryIndex' which has an int value range from 1 to 100.

I confirmed that the plotModel has one Series count attached, and that the Series has 100 items in it.

What I have done so far is I have collected a small sample frame of bitmap images. Resized then all to 128 x 128. Extracted all the pixel colours to a dictionary format, which allowed me to find the percentage/proportion values of the same color type across all bitmap images. I then passed those values into the Barseries ('Color' of each bar, 'Value' as a double number, 'CategoryIndex' from 1 to 100). BarSeries was added to PlotModel and PlotModel was added to PlotView.

My 'CategoryIndex' flows along the x-axis and 'Value' porportion/percentage flows along the x-axis (Initially tried to use ColumnSeries but that no longer exists). Hence my y-axis and x-axis labels are the opposite to what is the norm.

Tried figuring this out but no luck.

Main method is 'public partial class Form1 : Form' and contains the following code

public void HistogramPlot()
{
    Histogram histogram = new Histogram();

    Dictionary<Color, Double> colorProportionAllImages = histogram.Compute(_resizedbitmapFlowersArray);

    histogram.DisplayColorHistogram(colorProportionAllImages);

    histogram.Show();

}

This calls the class 'public class Histogram : Window' which has the following code

using OxyPlot.Axes;
using OxyPlot.Series;
using OxyPlot;
using System;
using System.Collections.Generic;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using OxyPlot.WindowsForms;
using System.Windows;
using System.Windows.Controls;
using Accord.Statistics.Visualizations;

namespace Sunflower_Recognition
{
    public class Histogram : Window
    {
        public Histogram()
        {
        // Leave Empty
        }

        /// <summary>
        /// Creating a proportional value of how often the same color value occurred thoughout all bitmap flower images 
        /// </summary>
        /// <param name="colorImagesResized">Bitmap array</param>
        /// <returns>Dictionary of all the 'key' color values and a porportional datum of those key color values</returns>
        public Dictionary<Color, double> Compute(Bitmap[] colorImagesResized)
        {
            // Create a Dictionary that will hold a color value 'key' and
            // a proportion representation of the color value (number of times that color value has occurred) 
            Dictionary<Color, double> histogramDictionary = new Dictionary<Color, double>();

            // To create a proportion range between 0 to 1 we need to know how many pixels, in total, we will be analysing
            int numPixels = colorImagesResized[0].Width * colorImagesResized[0].Height * colorImagesResized.Length;

            // Extracting each Bitmap image
            foreach (Bitmap image in colorImagesResized)
            {
                for (int y = 0; y < image.Height; y++)
                {
                    for (int x = 0; x < image.Width; x++)
                    {
                        // Extracting each pixel color
                        Color pixelColor = image.GetPixel(x, y);

                        // No 'duplicate key values' allowed so we first check for duplicates by 
                        // comparing an actual pixel color value against the existing keys
                        if (!histogramDictionary.ContainsKey(pixelColor))
                        {
                            // No duplicate key exists so we add a new key with default datum of 0.0
                            histogramDictionary[pixelColor] = 0.0;
                        }

                        // Increasing the datum count for that 'key color value' by 1 
                        histogramDictionary[pixelColor] += 1;
                    }
                }
            }

            // Create a new dictionary to hold the normalized/proportioned histogram data
            Dictionary<Color, double> histogramColorProportions = new Dictionary<Color, double>();

            // Normalize the histogram by dividing each frequency count by the total number of pixels analysed
            foreach (KeyValuePair<Color,double> keyValue in histogramDictionary)
            {
                // We now get each datum value from each key and alter the number to a proportional percentage value
                double proportionValue = (keyValue.Value / numPixels) * 100;

                histogramColorProportions.Add(keyValue.Key, proportionValue);
            }

            return histogramColorProportions;
        }

        public void DisplayColorHistogram(Dictionary<Color, double> histogramColorProportions)
        {
            // Create a new plot model
            PlotModel plotHistogramModel = new OxyPlot.PlotModel();

            // ***************** Axis formation
            // Create a new 'category' x-axis for displaying the color keys
            // We will display these key 'datum' values on the left side of the plot graph, as a range from 0.0 to 1.0
            CategoryAxis colorProportionAxis = new CategoryAxis();
            colorProportionAxis.Position = AxisPosition.Bottom;
            colorProportionAxis.Title = "Proportion (0 to 1)";

           // Create a new value y-axis for the key color values (frequencies) which will be a range from 0 to 255
            LinearAxis colorRangeAxis = new LinearAxis();
            colorRangeAxis.Position = AxisPosition.Left;
            colorRangeAxis.Title = "Color range (0 to 255)";
            colorRangeAxis.MinimumPadding = 0;
            colorRangeAxis.MaximumPadding = 0.1;

            colorRangeAxis.Minimum = 0;
            colorRangeAxis.Maximum = 3.0;

            // Add the axes to the plot model
            plotHistogramModel.Axes.Add(colorProportionAxis);
            plotHistogramModel.Axes.Add(colorRangeAxis);

            // Create a new column series to represent the color histogram
            BarSeries histogramSeries = new BarSeries();
            histogramSeries.Title = "Flower colors by proportion";
            // Is wil ensure that the columns are stacked side by side
            histogramSeries.IsStacked = false;

            int indexRange = 0;
            // Add data points from this histogram dictionary to the histogram barseries
            foreach (KeyValuePair<Color, double> keyValue in histogramColorProportions)
            {
                // Convert the System.Drawing.Color value (A=255, R=58, G=58, B=58) to OxyColor (ff3a3a3a)
                OxyColor oxyColor = OxyColor.FromRgb(keyValue.Key.R, keyValue.Key.G, keyValue.Key.B);

                // Add a new data point to the histogram series with the summation as the category index and the frequency as the value
                histogramSeries.Items.Add(new BarItem { Color = oxyColor, Value = keyValue.Value, CategoryIndex = indexRange++});
            }

            System.Windows.MessageBox.Show("Number of Items in 'histogramSeries: " + histogramSeries.Items.Count);  // !00 Items

            // Add the histogram series to the plot model
            plotHistogramModel.Series.Add(histogramSeries);  

            System.Windows.MessageBox.Show("Number of Series in the PlotModel: " + plotHistogramModel.Series.Count);  // 1 series in the plotmodel

            // Create a new plot view and set its model to the plot model
            PlotView plotView = new OxyPlot.WindowsForms.PlotView();
            plotView.Width = 10;
            plotView.Height = 800;
            plotView.Model = plotHistogramModel;

        }
    }

}