Applies to: Nevron Chart for .NET
How to enable sampling for the line series chart?
Nevron Chart Sampling feature allows plotting of line charts with hundreds of thousands of data points. When using sampling the line will automatically resample the data storage depending on the size of the chart on the screen. This allows for the visualization of massive amount of data. Enabling the line series sampling will also significantly improve your performance.
Figure 1: Sampled Line Series Chart
The following example produces 4 line series, each one with 100k data points:
[C#]
using System;
using System.Drawing;
using System.Windows.Forms;
using Nevron.Chart;
using Nevron.GraphicsCore;
...
private void Form1_Load(object sender, EventArgs e)
{
// no legend
nChartControl1.Legends.Clear();
// configure the chart
NChart Chart = nChartControl1.Charts[0];
Chart.Dock = DockStyle.Fill;
Chart.DockMargins = new NMarginsL(5, 20, 5, 20);
Chart.BoundsMode = BoundsMode.Stretch;
// add interlaced stripe to the Y axis
NScaleStripStyle stripStyle = new NScaleStripStyle(new NColorFillStyle(Color.FromArgb(155, 221, 221, 221)), null, true, 0, 0, 1, 1);
stripStyle.ShowAtWalls = new ChartWallType[] { ChartWallType.Back };
stripStyle.Interlaced = true;
((NStandardScaleConfigurator)Chart.Axis(StandardAxis.PrimaryY).ScaleConfigurator).StripStyles.Add(stripStyle);
// add a line series1
NLineSeries Line1 = (NLineSeries)Chart.Series.Add(SeriesType.Line);
Line1.Name = "Line Series1";
Line1.BorderStyle.Color = Color.Red;
Line1.InflateMargins = true;
Line1.DataLabelStyle.Visible = false;
Line1.MarkerStyle.Visible = false;
Line1.SamplingMode = SeriesSamplingMode.Enabled;
// add a line series2
NLineSeries Line2 = (NLineSeries)Chart.Series.Add(SeriesType.Line);
Line2.Name = "Line Series2";
Line2.BorderStyle.Color = Color.Green;
Line2.InflateMargins = true;
Line2.DataLabelStyle.Visible = false;
Line2.MarkerStyle.Visible = false;
Line2.SamplingMode = SeriesSamplingMode.Enabled;
// add a line series3
NLineSeries Line3 = (NLineSeries)Chart.Series.Add(SeriesType.Line);
Line3.Name = "Line Series3";
Line3.BorderStyle.Color = Color.Blue;
Line3.InflateMargins = true;
Line3.DataLabelStyle.Visible = false;
Line3.MarkerStyle.Visible = false;
Line3.SamplingMode = SeriesSamplingMode.Enabled;
// add a line series4
NLineSeries Line4 = (NLineSeries)Chart.Series.Add(SeriesType.Line);
Line4.Name = "Line Series4";
Line4.BorderStyle.Color = Color.Orange;
Line4.InflateMargins = true;
Line4.DataLabelStyle.Visible = false;
Line4.MarkerStyle.Visible = false;
Line4.SamplingMode = SeriesSamplingMode.Enabled;
// add data to the line series
Random rand = new Random();
AddNewData(Line1, 100000);
AddNewData(Line2, 100000);
AddNewData(Line3, 100000);
AddNewData(Line4, 100000);
}
private void AddNewData(NLineSeries line, int count)
{
Random rand = new Random();
double prevYVal = 0;
double prevXVal = 0;
double[] yValues = new double[count];
double magnitude = 0.01 + rand.NextDouble() * 5;
// continuous
double angle = 0;
double phase = (Math.PI * 2 * rand.NextDouble()) / count + 0.0001;
for (int i = 0; i < count; i++)
{
double yStep = Math.Sin(angle) * magnitude;
double xStep = 0.01 + rand.NextDouble() * magnitude;
if (xStep < 0)
{
xStep = 0;
}
angle += phase;
prevXVal += xStep;
yValues[i] = prevYVal + yStep;
}
line.Values.AddRange(yValues);
}
[VB.NET]
Imports System
Imports System.Drawing
Imports System.Windows.Forms
Imports Nevron.Chart
Imports Nevron.GraphicsCore
...
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
' no legend
NChartControl1.Legends.Clear()
' configure the chart
Dim Chart As NChart = NChartControl1.Charts(0)
Chart.Dock = DockStyle.Fill
Chart.DockMargins = New NMarginsL(5, 20, 5, 20)
Chart.BoundsMode = BoundsMode.Stretch
' add interlaced stripe to the Y axis
Dim stripStyle As New NScaleStripStyle(New NColorFillStyle(Color.FromArgb(155, 221, 221, 221)), Nothing, True, 0, 0, 1, 1)
stripStyle.ShowAtWalls = New ChartWallType() {ChartWallType.Back}
stripStyle.Interlaced = True
DirectCast(Chart.Axis(StandardAxis.PrimaryY).ScaleConfigurator, NStandardScaleConfigurator).StripStyles.Add(stripStyle)
' add a line series1
Dim Line1 As NLineSeries = DirectCast(Chart.Series.Add(SeriesType.Line), NLineSeries)
Line1.Name = "Line Series1"
Line1.BorderStyle.Color = Color.Red
Line1.InflateMargins = True
Line1.DataLabelStyle.Visible = False
Line1.MarkerStyle.Visible = False
Line1.SamplingMode = SeriesSamplingMode.Enabled
' add a line series2
Dim Line2 As NLineSeries = DirectCast(Chart.Series.Add(SeriesType.Line), NLineSeries)
Line2.Name = "Line Series2"
Line2.BorderStyle.Color = Color.Green
Line2.InflateMargins = True
Line2.DataLabelStyle.Visible = False
Line2.MarkerStyle.Visible = False
Line2.SamplingMode = SeriesSamplingMode.Enabled
' add a line series3
Dim Line3 As NLineSeries = DirectCast(Chart.Series.Add(SeriesType.Line), NLineSeries)
Line3.Name = "Line Series3"
Line3.BorderStyle.Color = Color.Blue
Line3.InflateMargins = True
Line3.DataLabelStyle.Visible = False
Line3.MarkerStyle.Visible = False
Line3.SamplingMode = SeriesSamplingMode.Enabled
' add a line series4
Dim Line4 As NLineSeries = DirectCast(Chart.Series.Add(SeriesType.Line), NLineSeries)
Line4.Name = "Line Series4"
Line4.BorderStyle.Color = Color.Orange
Line4.InflateMargins = True
Line4.DataLabelStyle.Visible = False
Line4.MarkerStyle.Visible = False
Line4.SamplingMode = SeriesSamplingMode.Enabled
' add data to the line series
Dim rand As New Random()
AddNewData(Line1, 100000)
AddNewData(Line2, 100000)
AddNewData(Line3, 100000)
AddNewData(Line4, 100000)
End Sub
Private Sub AddNewData(ByVal line As NLineSeries, ByVal count As Integer)
Dim rand As New Random()
Dim prevYVal As Double = 0
Dim prevXVal As Double = 0
Dim yValues As Double() = New Double(count - 1) {}
Dim magnitude As Double = 0.01 + rand.NextDouble() * 5
' continuous
Dim angle As Double = 0
Dim phase As Double = (Math.PI * 2 * rand.NextDouble()) / count + 0.0001
For i As Integer = 0 To count - 1
Dim yStep As Double = Math.Sin(angle) * magnitude
Dim xStep As Double = 0.01 + rand.NextDouble() * magnitude
If xStep < 0 Then
xStep = 0
End If
angle += phase
prevXVal += xStep
yValues(i) = prevYVal + yStep
Next
line.Values.AddRange(yValues)
End Sub
Article ID: 138, Created On: 11/23/2010, Modified: 12/1/2010