Negative Bar Stack in WinForms

Thia post will demonstrate how to create a horizontal stacked bar chart with negative values. We will use the Charting for WinForms component and the final chart looks like this:

Negative Stacked Bar Chart in WinForms with the Chart Control

Negative Stacked Bar Chart in WinForms with the Chart Control

I. Data

The chart will use four series. The first two series are the ones that you clearly see – the red and blue one. We initialize two data arrays with random values that represent the data:

var firstBarX = new List<double>(11);
var secondBarX = new List<double>(11);

Random r = new Random();
            
for(int i = 0; i < 11; i++)
   {
       firstBarX.Add(2.2 + r.NextDouble());
       secondBarX.Add(2.4 + r.NextDouble());
    }

We need a list with data values that are exactly the same as the first series, but are negative. They will provide a transparent initial series, whose bars will offset the first, red, series as much as the value of the red bar should be:

//generate data for the transparent series
var transparentBarX = new List<double>(firstBarX.Count);

for (var i = 0; i < firstBarX.Count; i++)			
    transparentBarX.Add(0 - firstBarX[i]);

The data for the Y-axis is very simple. We just need a list with the numbers from 1 to 12:

//data for the Y-axis
var barY = new List<double>();
for (int i = 1; i < 12; i++)			
	barY.Add(i);

II. Labels
We will create two lists with the labels that we will show – for the two axis. The labels for the Y-axis will be used as tooltips as well. We just initialize two string lists:

//initialize labels for the X axis
var ageLabels = new List<string>() { "0-5", "6-11", "12-17", "18-23", "24-29", "30-35",
		   "36-41", "42-47", "48-53", "54-59", "60-65" };

//initialize labels for the Y axis.
var percentageLabels = new List<string> { "5%", "4%", "3%", "2%", "1%", "0%", 				"1%", "2%", "3%", "4%", "5%", };

We will use this label lists in the next section, when we create the series.

III. Series

We will use 4 series, of type Series2D. This series is useful for its SupportedLabels property – it allows us to specify what the labels of the series would be used for. We start with the transparent series. Its labels will be used for custom labels at the Y-axis:

var seriesTransparent = new MindFusion.Charting.Series2D(transparentBarX, barY, ageLabels);
seriesTransparent.SupportedLabels = MindFusion.Charting.LabelKinds.YAxisLabel;
seriesTransparent.Title = "";

We use for X-data the negative values you remember from the previous paragraph. The age labels are those that provide the data for the axis.

Then we initialize the two series for the chart data:

var seriesFirst = new MindFusion.Charting.Series2D(firstBarX, barY, ageLabels);
seriesFirst.SupportedLabels = MindFusion.Charting.LabelKinds.ToolTip;
seriesFirst.Title = "Female";

var seriesSecond = new MindFusion.Charting.Series2D(secondBarX, barY, ageLabels);
seriesSecond.SupportedLabels = MindFusion.Charting.LabelKinds.ToolTip;
seriesSecond.Title = "Male";

The last series that we create is just to provide data for the X-axis and we set its SupportedLabels property to MindFusion.Charting.LabelKinds.XAxisLabel. The X-data for this series corresponds to the coordinates of the X-labels, that’s why set the numbers from -5 to 5 as X-data:

var firstParamList = new List<double>();
      for (int i = -5; i < 6; i++)			
	 firstParamList.Add(i);

The Y-data could be all zeros, we won’t use them anyway.

var secondParamList = new List<double>();
    for (int i = 0; i < 12; i++)			
	secondParamList.Add(0);

And we create the series this way:

//the purpose of this series is to only supply the Xaxis labels, it is transparent.	
var seriesThird = new MindFusion.Charting.Series2D(firstParamList, secondParamList, percentageLabels);           	
seriesThird.SupportedLabels = MindFusion.Charting.LabelKinds.XAxisLabel;
seriesThird.Title = "";

After you have created all series, you should add them to the Series collection of the BarChart:

barChart.Series = new ObservableCollection<Series>
	{ seriesTransparent, seriesFirst, seriesSecond, seriesThird };
           	

IV. Axes and Grid

We need to fix the divisions of the X-axis if we want to show a grid and the grid to be neatly aligned with the axes. We will set the min value to be -6, the interval 1 and the max value to be 6:

barChart.XAxis.Interval = 1;
barChart.XAxis.MinValue = -6;
barChart.XAxis.MaxValue = 6;		

We will use three more properties to hide the interval labels at both axes, show ticks on them and set a title for each axis:

barChart.XAxis.Title = "Percentage of the Population";
barChart.YAxis.Title = "Ages";
			
barChart.ShowYCoordinates = false;
barChart.ShowXCoordinates = false;

barChart.ShowXTicks = true;
barChart.ShowYTicks = true;

Finally, we have to set the grid and specify that the bars are horizontal:

barChart.GridType = GridType.Vertical;
barChart.HorizontalBars = true;

V. Styling

Styling the chart is done though the SeriesSyle property of the Plot. You can assign to it different series types, you can check the list at the ISeriesStyle interface page in the documentation:

barChart.Plot.SeriesStyle = new PerSeriesStyle()
{
	Strokes = new List<MindFusion.Drawing.Brush> {
		firstBrush, new SolidBrush(Color.FromArgb(179, 0, 0)), 
                new SolidBrush(Color.FromArgb(0, 0, 102)), firstBrush
		},
		StrokeThicknesses = new List<double> {
			 0,2,2,0
		},
		Fills = new List<MindFusion.Drawing.Brush>()
		{
			firstBrush, secondBrush, thirdBrush, firstBrush
	}
};

This style indicates that each brush from its collection will be used for one series in the chart. We assign to it 4 brushes and 4 strokes. The first brush is transparent, the second one is red, the other is blue and the last one is black – we won’t draw with it anyway.

The Theme property of the chart holds a lot of options for customizing the appearance. Here are just a few of them:

barChart.Theme.LegendBorderStrokeThickness = 1;
barChart.Theme.LegendBorderStroke = new SolidBrush(Color.Black);
barChart.Theme.GridColor2 = Color.White;
barChart.Theme.GridColor1 = Color.FromArgb(250, 250, 250);
barChart.Theme.GridLineColor = Color.FromArgb(153, 153, 153);
barChart.Theme.PlotBackground = new SolidBrush(Color.FloralWhite);
...........
..........

And that’s the end of this step-by-step guide. You can download the sample together will all necessary libraries from this link:

Download Negative Stack Bar Chart in CS Sample

About MindFusion Charting for WinForms: A versatile dashboard component that provides your WinForms application with the ability to create fascinating charts, interactive dashboards and practical gauges. The component combines a flexible API that allows custom combination of chart components to build any type of chart you want. You can add as many axes of any type you want, combine various chart series into a single chart with different data providers each. The control also supports pan and zoom, scroll, unlimited number of legends, grid and a dashboard panel. Linear and oval gauges complete the tool set and guarantee every feature you might need to build the perfect gauge, chart of any type or dashboard in WinForms is right at your fingertips. Learn more at https://mindfusion.eu/winforms-chart.html

Line Chart with DateTime Data in ASP.NET

In this post we demonstrate how to use MindFusion.Charting for ASP.NET component to create a line chart that shows the number of unique visitors to a store/website in a period of 6 weeks.

Data

The data for the X-axis are DateTime values. We create an array with the DateTime values that we’ll use and add it to the XData property of our chart. Before that we have to delete the predefined array that is added when the control is dropped at the form:

DateTime dt1 = new DateTime(2013, 6, 14);
DateTime dt2 = new DateTime(2013, 6, 7);
DateTime dt3 = new DateTime(2013, 5, 31);
DateTime dt4 = new DateTime(2013, 5, 24);
DateTime dt5 = new DateTime(2013, 5, 17);
DateTime dt6 = new DateTime(2013, 5, 10);

ArrayList data = new ArrayList() { dt1, dt2, dt3, dt4, dt5, dt6 };
LineChart1.XData.Clear();
LineChart1.XData.Add(data);

Next, we must make some adjustments in the settings for the X-axis to tell the control that DateTime data is used. We set the DataFormat property to DateTime and we specify the time range for the axis. This is how we do this:

LineChart1.XAxisSettings.DataFormat = MindFusion.Charting.DataFormat.DateTime;

LineChart1.XAxisSettings.StartDateTime = new DateTime(2013, 5, 3);
LineChart1.XAxisSettings.EndDateTime = new DateTime(2013, 6, 20);
//set the interval to one week - 7 days
LineChart1.XAxisSettings.TimeSpan = new TimeSpan(7, 0, 0, 0);

The data for the Y-axis are numbers. We can set them through the property grid or set them in code.

LineChart1.YData.Clear();
ArrayList data1 = new ArrayList() { 56, 13, 45, 17, 82, 22 };
LineChart1.YData.Add(data1);

The X-axis

First, we must change the LabelType property of XAxisSettings from “ChartData”, which is the default to “AutoScale”. This will make the axis show the time range we’ve set in code above. Then, we change how the DateTime values will be formatted. The Default DateTimeFormat shows the full time and date and is not suitable. We change it to “LongDate”, which does not draw any time.

XAxisSettings-DateTimeFormat="LongDate" 
XAxisSettings-DrawTicksUniformly="False" XAxisSettings-DrawZero="True" 
XAxisSettings-LabelBrush="s:#FF696969" XAxisSettings-LabelOffset="10" 
XAxisSettings-LabelType="AutoScale" XAxisSettings-TitleLabel="Week" 
XAxisSettings-TitleLabelBrush="s:#FF696969" XAxisSettings-TitleLabelOffset="10" 

We type “Week” as TitleLabel for the axis and set the DrawZero property to true to show the first label, which is otherwise omitted.

Upon preview we notice that the labels are too close to the axis, that’s why we use LabelOffset and TitleLabelOffset to add some space before them. Finally, we change the color of the labels, to make them dark gray rather than black.

The Y-axis

Customizing the Y-axis is rather simple. We change the interval with AxisDelta to 5 and increase the MaxValue to 100. We don’t need decimal fractions for the labels, that’s why we change the NumberFormat. We add a TitleLabel and change its orientation with TitleLabelOrientation. Finally we use LabelBrush and TitleLabelBrush to change the colors of the labels – we use the same brushes as for the X-axis.

YAxisSettings-AxisDelta="5" 
YAxisSettings-LabelBrush="s:#FF696969" 
YAxisSettings-MaxValue="100" YAxisSettings-NumberFormat="Fixed_point_0Digits" 
YAxisSettings-TitleLabel="Unique Visitors" 
YAxisSettings-TitleLabelBrush="s:#FF696969" 
YAxisSettings-TitleLabelOrientation="BottomToTop"

The Grid

Initially the chart shows no grid – but we want to show a grid. That’s why we change GridType to “Crossed” and set a GridPen. The dark gray background of the plot area together with its outlining are set with PlotAreaOutlinePen and PlotAreaBrush.

GridPen="n:0/#FFE1E1E1/0/0/0//0/0/10/" GridType="Crossed" PlotAreaBrush="s:#FFC0C0C0" 
PlotAreaOutlinePen="n:0/#FF787878/0/0/0//0/0/10/"

This is the code that was generated by the designer because we set the properties through the property grid. If we set them with code, it will be:

LineChart1.GridPen = new MindFusion.Drawing.Pen(Color.FromArgb(225,225,225));
LineChart1.GridType = MindFusion.Charting.GridType.Crossed;
LineChart1.PlotAreaBrush = new MindFusion.Drawing.SolidBrush(Color.FromArgb(192, 192, 192));
LineChart1.PlotAreaOutlinePen = new MindFusion.Drawing.Pen(Color.FromArgb(120, 120, 120));


The Line Series

We want scatters at data points and we want to show labels above those scatters. The LabelType property lets us set the type to be both line and scatters:

LineChart1.LineType = MindFusion.Charting.LineTypes.Line | MindFusion.Charting.LineTypes.Scatter;

This is the default type, so you don’t need to set it if you have not changed it before. We use ShapeBrushes, ShapePens and ShapeSizes to set the brushes and size of the scatters. We can do this in the property grid or in code. Finally, we want to show labels above scatters. We use LabelType and LabelFormat to set what kind of labels are drawn and since our labels are numbers – how they are formatted.

LabelBorder="RoundedRect" LabelBorderBackground="s:#FFFFFFE0" LabelBorderOutline="n:0/#FF787878/0/0/0//0/0/10/" LabelFormat="Fixed_point_0Digits" LabelType="Data"

In code you write:

LineChart1.LabelBorder = MindFusion.Charting.Border.RoundedRect;
LineChart1.LabelBorderBackground = new MindFusion.Drawing.SolidBrush(Color.FromArgb(255, 255, 224));
LineChart1.LabelBorderOutline = new MindFusion.Drawing.Pen(Color.FromArgb(120, 120,120));
LineChart1.LabelFormat = MindFusion.Charting.NumberFormat.Fixed_point_0Digits;
LineChart1.LabelType = MindFusion.Charting.LabelType.Data;

Here is the final chart:

Line chart with DateTime values in ASP.NET

Line chart with DateTime values in ASP.NET

You can download the sample from this link:

Download Line Chart for ASP.NET Sample

The trial version of the component is available from here:

MindFusion.Charting for ASP.NET Trial Version Download