How to create a tornado chart with C++

Introduction

A tornado chart, also known as a tornado diagram or tornado graph, is a type of data visualization that is often used for sensitivity analysis in Excel. It helps you understand the impact of changing variables on a particular outcome or result.

How to Create a Tornado Chart in Excel

You can create a tornado chart in Excel by following these steps:

1. Select the data and go to Insert → Charts → Insert Column or Bar Chart → Stacked Bar Chart. Click on it.
   
   
2. Change the Y‑axis: Right‑click on the Y‑axis. Click on Format Axis. In Labels, click on the label position drop‑down and select the Low item.
   
   
3. Select any bar and go to the Formatting pane. Set an appropriate gap width.
   
   
4. Let’s remove the minus sign (‑) from the tornado chart. Select the X‑axis, go to Formatting, and in the Axis Options click Number. In Category, select Custom, and in the Format Code type ###0,###0. Click Add.
   
   
5. Click on the Y‑axis and go to the Axis Options. In the Axis Options, check the Categories in reverse order box.
   
   

How to Add a Tornado Chart with Aspose.Cells

Please see the following sample code. It loads the sample Excel file that contains some sample data. It then creates the stacked bar chart based on the initial data and sets relevant properties. Finally, it saves the workbook to the output XLSX format. The following screenshot shows the tornado chart created by Aspose.Cells in the output Excel file.

Sample Code

#include <iostream>
#include "Aspose.Cells.h"
using namespace Aspose::Cells;

int main()
{
    Aspose::Cells::Startup();

    // Source directory path
    U16String srcDir(u"..\\Data\\01_SourceDirectory\\");

    // Output directory path
    U16String outDir(u"..\\Data\\02_OutputDirectory\\");

    // Path of input Excel file
    U16String inputFilePath = srcDir + u"sample.xlsx";

    // Path of output Excel file
    U16String outputFilePath = outDir + u"out.xlsx";

    // Create workbook
    Workbook wb(inputFilePath);

    // Get the first worksheet
    Worksheet sheet = wb.GetWorksheets().Get(0);

    // Get the chart collection from the worksheet
    ChartCollection charts = sheet.GetCharts();

    // Add a bar chart
    int index = charts.Add(ChartType::BarStacked, 8, 1, 24, 8);
    Chart chart = charts.Get(index);

    // Set data for the bar chart
    chart.SetChartDataRange(u"A1:C7", true);

    // Set properties for the bar chart
    chart.GetTitle().SetText(u"Tornado chart");
    chart.SetStyle(2);
    chart.GetPlotArea().GetArea().SetForegroundColor(Color::White());
    chart.GetPlotArea().GetBorder().SetColor(Color::White());
    chart.GetLegend().SetPosition(LegendPositionType::Bottom);

    // Set properties for the category axis
    chart.GetCategoryAxis().SetTickLabelPosition(TickLabelPositionType::Low);
    chart.GetCategoryAxis().SetIsPlotOrderReversed(true);

    // Set gap width
    chart.SetGapWidth(10);

    // Set properties for the value axis
    Axis valueAxis = chart.GetValueAxis();
    valueAxis.GetTickLabels().SetNumberFormat(u"#,##0;#,##0");

    // Save the workbook
    wb.Save(outputFilePath);

    std::cout << "Chart created successfully!" << std::endl;

    Aspose::Cells::Cleanup();
}