void addTrendlineOption(string text, EventHandler handler)
{
OptionInfo option = new OptionInfo(text, handler);
Trendlines.Add(option);
this.AddOption(option);
}
// Function that creates the plot
public static void plotChart(string columnTitle)
{
Range chartRange;
object misValue = System.Reflection.Missing.Value;
// Creates the chart
ChartObjects xlCharts = (ChartObjects)ExcelExecutions.xlWorksheet.ChartObjects(Type.Missing);
ChartObject myChart = xlCharts.Add(250, 50, 600, 350);
Chart xlChart = myChart.Chart;
xlChart.ChartType = XlChartType.xlXYScatter;
// Gets the range for the column title
Range XcolumnTitleLocation = findCell(ExcelExecutions.xTitle);
Range YcolumnTitleLocation = findCell(columnTitle);
// The title for the x- and y-axis
Axis xAxis = xlChart.Axes(XlAxisType.xlCategory, XlAxisGroup.xlPrimary) as Axis;
Axis yAxis = xlChart.Axes(XlAxisType.xlValue, XlAxisGroup.xlPrimary) as Axis;
xAxis.HasTitle = true;
yAxis.HasTitle = true;
xAxis.AxisTitle.Text = XcolumnTitleLocation.Value;
yAxis.AxisTitle.Text = YcolumnTitleLocation.Value;
// The values for the chart
string xColumnPrefix = ExcelExecutions.columnNames[XcolumnTitleLocation.Column - 1];
string yColumnPrefix = ExcelExecutions.columnNames[YcolumnTitleLocation.Column - 1];
Range xValues = ExcelExecutions.xlWorksheet.Range[xColumnPrefix + "2", (xColumnPrefix + ExcelExecutions.xlRange.Rows.Count.ToString())];
Range yvalues = ExcelExecutions.xlWorksheet.Range[yColumnPrefix + "2", (yColumnPrefix + ExcelExecutions.xlRange.Rows.Count.ToString())];
// Assigns the value to the chart
SeriesCollection seriesCollection = xlChart.SeriesCollection();
Series pointPlot = seriesCollection.NewSeries();
pointPlot.XValues = xValues;
pointPlot.Name = columnTitle;
pointPlot.Values = yvalues;
// Creates trendline(regression)
Trendlines trendlines = (Trendlines)pointPlot.Trendlines(Type.Missing);
Trendline linearRegression = trendlines.Add(XlTrendlineType.xlLinear);
linearRegression.DisplayEquation = true;
linearRegression.DisplayRSquared = true;
saveChart(xlChart, pointPlot.Name);
}