private double FindStdDev(IList <object> data, double mean)
{
double sum = 0;
for (var i = 0; i < data.Count; i++)
{
ZonesData item = (ZonesData)data[i];
var d = item.Score - mean;
sum += d * d;
}
return(System.Math.Sqrt(sum / data.Count));
}
// a method to create a list of zones sample objects of type ChartPoint
public static IList <object> getZonesList(int nStudents, int nMaxPoints)
{
List <object> list = new List <object>();
Random random = new Random();
for (int i = 0; i < nStudents; i++)
{
ZonesData point = new ZonesData(i, nMaxPoints * 0.5 * (1 + random.NextDouble()));
list.Add(point);
}
return(list);
}
protected override void OnCreate(Bundle savedInstanceState)
{
base.OnCreate(savedInstanceState);
SetContentView(Resource.Layout.activity_zones);
var toolbar = FindViewById <Toolbar>(Resource.Id.toolbar);
SetSupportActionBar(toolbar);
SupportActionBar.Title = GetString(Resource.String.zones);
SupportActionBar.SetDisplayHomeAsUpEnabled(true);
SupportActionBar.SetHomeButtonEnabled(true);
// initializing widget
mChart = this.FindViewById <FlexChart>(Resource.Id.zonesFlexchart);
mChart.BindingX = "Number";
mChart.ChartType = ChartType.Scatter;
int nStudents = 20;
int nMaxPoints = 100;
IList <object> data = ZonesData.getZonesList(nStudents, nMaxPoints);
mChart.ItemsSource = data;
mChart.Tapped += MChart_Tapped;
mChart.AxisX.Title = "student number";
mChart.AxisY.Title = "student accumulated points";
double mean = this.FindMean(data);
double stdDev = this.FindStdDev(data, mean);
List <double> scores = new List <double>();
foreach (ZonesData item in data)
{
scores.Add(item.Score);
}
scores.Sort((x, y) => y.CompareTo(x));
var zones = new double[]
{
scores[this.GetBoundingIndex(scores, 0.85)],
scores[this.GetBoundingIndex(scores, 0.75)],
scores[this.GetBoundingIndex(scores, 0.25)],
scores[this.GetBoundingIndex(scores, 0.05)]
};
Integer[] colors = new Integer[]
{
new Integer(Color.Argb(255, 255, 192, 192)),
new Integer(Color.Argb(255, 55, 228, 228)),
new Integer(Color.Argb(255, 255, 228, 128)),
new Integer(Color.Argb(255, 128, 255, 128)),
new Integer(Color.Argb(255, 128, 128, 255)),
};
for (var i = 4; i >= 0; i--)
{
float y = (float)(i == 4 ? mean + 2 * stdDev : zones[i]);
PointF[] sdata = new PointF[data.Count];
for (int j = 0; j < data.Count; j++)
{
sdata[j] = new PointF(j, y);
if (i == 0)
{
System.Console.WriteLine(j + "=" + y);
}
}
string seriesName = ((char)((short)'A' + 4 - i)).ToString();
var series = new ChartSeries();
series.Chart = mChart;
series.SeriesName = seriesName;
series.Binding = "Y";
series.ItemsSource = sdata;
series.BindingX = "X";
series.ChartType = ChartType.Area;
series.Style = new ChartStyle();
series.Style.Fill = new Color(colors[i].IntValue());
mChart.Series.Add(series);
}
ChartSeries scoreSeries = new ChartSeries();
scoreSeries.Chart = mChart;
scoreSeries.SeriesName = "raw score";
scoreSeries.Binding = "Score";
scoreSeries.BindingX = "Number";
mChart.Series.Add(scoreSeries);
for (var i = -2; i <= 2; i++)
{
var y = mean + i * stdDev;
string seriesName = string.Empty;
if (i > 0)
{
seriesName = "m+" + i + "s";
}
else if (i < 0)
{
seriesName = "m" + i + "s";
}
else
{
seriesName = "mean";
}
PointF[] sdata = new PointF[data.Count];
for (int j = 0; j < data.Count; j++)
{
sdata[j] = new PointF(j, (float)y);
}
var series = new ChartSeries();
series.Chart = mChart;
series.SeriesName = seriesName;
series.Binding = "Y";
series.ItemsSource = sdata;
series.BindingX = "X";
series.ChartType = ChartType.Line;
series.Style = new ChartStyle();
series.Style.StrokeThickness = 2;
series.Style.Stroke = Color.Rgb(0x20, 0x20, 0x20);
mChart.Series.Add(series);
}
}
public override void ViewDidLoad()
{
base.ViewDidLoad();
// Perform any additional setup after loading the view, typically from a nib.
chart = new FlexChart();
chart.BindingX = "Number";
chart.ChartType = ChartType.Scatter;
chart.AxisX.Title = "student number";
chart.AxisY.Title = "student accumulated points";
int nStudents = 20;
int nMaxPoints = 100;
IList <object> data = ZonesData.getZonesList(nStudents, nMaxPoints);
chart.ItemsSource = data;
this.Add(chart);
double mean = this.FindMean(data);
double stdDev = this.FindStdDev(data, mean);
List <double> scores = new List <double>();
foreach (ZonesData item in data)
{
scores.Add(item.Score);
}
scores.Sort((x, y) => y.CompareTo(x));
var zones = new double[]
{
scores[this.GetBoundingIndex(scores, 0.95)],
scores[this.GetBoundingIndex(scores, 0.75)],
scores[this.GetBoundingIndex(scores, 0.25)],
scores[this.GetBoundingIndex(scores, 0.05)]
};
NSArray colors = NSArray.FromObjects(UIColor.FromRGBA(0.99f, 0.75f, 0.75f, 1.00f),
UIColor.FromRGBA(0.22f, 0.89f, 0.89f, 1.00f),
UIColor.FromRGBA(1.00f, 0.89f, 0.50f, 1.00f),
UIColor.FromRGBA(0.50f, 1.00f, 0.50f, 1.00f),
UIColor.FromRGBA(0.50f, 0.50f, 1.00f, 1.00f));
for (var i = 4; i >= 0; i--)
{
float y = (float)(i == 4 ? mean + 2 * stdDev : zones[i]);
IList <object> sdata = new List <object>();
for (int j = 0; j < data.Count; j++)
{
sdata.Add(new ZonesData((double)j, (double)y));
}
string seriesName = ((char)((short)'A' + 4 - i)).ToString();
ChartSeries series = new ChartSeries {
SeriesName = seriesName, Binding = "Y"
};
series.ItemsSource = sdata;
series.BindingX = "X";
series.ChartType = ChartType.Area;
series.Style = new ChartStyle {
Fill = colors.GetItem <UIColor>((nuint)i)
};
chart.Series.Add(series);
}
chart.Series.Add(new ChartSeries {
SeriesName = "raw score", Binding = "Score", BindingX = "Number"
});
for (var i = -2; i <= 2; i++)
{
var y = mean + i * stdDev;
string seriesName = string.Empty;
if (i > 0)
{
seriesName = "m+" + i + "s";
}
else if (i < 0)
{
seriesName = "m" + i + "s";
}
else
{
seriesName = "mean";
}
IList <object> sdata = new List <object>();
for (int j = 0; j < data.Count; j++)
{
sdata.Add(new ZonesData((double)j, (double)y));
}
ChartSeries series = new ChartSeries {
SeriesName = seriesName, Binding = "Y"
};
series.ItemsSource = sdata;
series.BindingX = "X";
series.ChartType = ChartType.Line;
series.Style = new ChartStyle {
Fill = UIColor.Black, StrokeThickness = 2
};
chart.Series.Add(series);
}
}