Is there a mechanism to bind a NFunctionCalculator to a dataset?

I'd like to attach a function calculator to a dataset that is currently being also bound to a chart.

Here is the binding for two line series to a dataset with three columns,

// First line
this->nChartControl2->DataBindingManager->AddBinding(0,0,"XValues",ds->Tables["laserdata"],"Tick");
this->nChartControl2->DataBindingManager->AddBinding(0,0,"Values",ds->Tables["laserdata"],"Gain");

// Second line
this->nChartControl2->DataBindingManager->AddBinding(0,1,"XValues",ds->Tables["laserdata"],"Tick"); this->nChartControl2->DataBindingManager->AddBinding(0,1,"Values",ds->Tables["laserdata"],"Photodiode");

I would like to add a third series for bollinger calculation that uses the NFunctionCalculator based on the "Photodiode" data from the dataset.

However, I have not been able to figure out a mechanism to create a function calculator using the data from a dataset (Photodiode column). And, how to bind the calculator results to the third bollinger type series.


Any thoughts are appreciated.

Thanks.

Hello Jay,

Currently there is no built-in functionality that lets you data bind a function calculator. You can do this manually by subscribing to the ColumnChanged event of the ds->Tables["laserdata"] table. The following example demonstrates this approach.


------------------------------------------------------------

using System;
using System.Data;
using System.Windows.Forms;
using Nevron.Chart;
using Nevron.Chart.Functions;


namespace JayVicory
{
public partial class Form1 : Form
{
Random rand = new Random();
NLineSeries line;
DataTable dataTable;
NFunctionCalculator calculator;
NDataSeries dataSeries;

public Form1()
{
InitializeComponent();

dataTable = new DataTable();
dataTable.Columns.Add("SomeColumn", typeof(double));
dataTable.Columns.Add("Photodiode", typeof(double));
dataTable.Columns.Add("AnotherColumn", typeof(double));
dataTable.Rows.Add(new object[] { 0, 22, 0 });
dataTable.Rows.Add(new object[] { 0, 42, 0 });
dataTable.Rows.Add(new object[] { 0, 14, 0 });
dataTable.Rows.Add(new object[] { 0, 24, 0 });
dataTable.Rows.Add(new object[] { 0, 31, 0 });
dataTable.ColumnChanged += new DataColumnChangeEventHandler(dt_ColumnChanged);

dataSeries = new NDataSeries(DataSeriesType.Double, "Photodiode");

calculator = new NFunctionCalculator();
calculator.Arguments.Add(dataSeries);
calculator.Expression = "BOLLINGER(Photodiode; 3; 2)";
}

private void Form1_Load(object sender, EventArgs e)
{
line = (NLineSeries)nChartControl1.Charts[0].Series.Add(SeriesType.Line);

UpdateLine();
}

void dt_ColumnChanged(object sender, DataColumnChangeEventArgs e)
{
if (e.Column.ColumnName == "Photodiode")
{
UpdateLine();
nChartControl1.Refresh();
}
}

void UpdateLine()
{
dataSeries.FillFromDataTable(dataTable, "Photodiode");
NDataSeries result = calculator.Calculate();
line.Values = result;
}

private void button1_Click(object sender, EventArgs e)
{
dataTable.Rows[2].ItemArray = new object[] { 0, rand.NextDouble() * 50, 0 };
}
}
}

------------------------------------------------------------

I hope this helps, please let me know if you have any questions or comments.


Best Regards,
Milen

Thanks Milen.

This seems like a reasonable solution, I didn't really think of this option. I'll give it a try and post the results.

Thanks again.

Best regards,

Jay.