Customize Chart Axes in Presentations on Android

Overview

This article explains how to customize chart axes in Aspose.Slides. It shows how to get actual axis values, swap data between axes, hide the vertical or horizontal axis for line charts, change the category axis type, set the date format for category axis values, rotate an axis title, set the axis position, and set the display unit of the value axis.

Get the Max Values on the Vertical Axis on Charts

Aspose.Slides for Android via Java allows you to obtain the minimum and maximum values on a vertical axis. Go through these steps:

  1. Create an instance of the Presentation class.
  2. Access the first slide.
  3. Add a chart with default data.
  4. Get the actual maximum value on the axis.
  5. Get the actual minimum value on the axis.
  6. Get the actual major unit of the axis.
  7. Get the actual minor unit of the axis.
  8. Get the actual major unit scale of the axis.
  9. Get the actual minor unit scale of the axis.

This sample code—an implementation of the steps above—shows you how to get the required values in Java:

import com.aspose.slides.*;

Presentation pres = new Presentation();
try {
	Chart chart = (Chart)pres.getSlides().get_Item(0).getShapes().addChart(ChartType.Area, 100, 100, 500, 350);
	chart.validateChartLayout();

	double maxValue = chart.getAxes().getVerticalAxis().getActualMaxValue();
	double minValue = chart.getAxes().getVerticalAxis().getActualMinValue();

	double majorUnit = chart.getAxes().getVerticalAxis().getActualMajorUnit();
	double minorUnit = chart.getAxes().getVerticalAxis().getActualMinorUnit();

	int majorUnitScale = chart.getAxes().getVerticalAxis().getActualMajorUnitScale();
	int minorUnitScale = chart.getAxes().getVerticalAxis().getActualMinorUnitScale();

	// Saves the presentation
	pres.save("MaxValuesVerticalAxis_out.pptx", SaveFormat.Pptx);
} finally {
	if (pres != null) pres.dispose();
}

Swap the Data between Axes

Aspose.Slides allows you to quickly swap the data between axes—the data represented on the vertical axis (y-axis) moves to the horizontal axis (x-axis) and vice versa.

This Java code shows you how to perform the data swap task between axes on a chart:

import com.aspose.slides.*;

Presentation pres = new Presentation();
try {
	IChart chart = pres.getSlides().get_Item(0).getShapes().addChart(ChartType.ClusteredColumn, 100, 100, 400, 300);

	// Loads the chart's default data into the workbook — switchRowColumn transposes the workbook,
	// so it must be populated first
	IChartDataWorkbook workbook = chart.getChartData().getChartDataWorkbook();

	//Switches rows and columns
	chart.getChartData().switchRowColumn();

	// Saves presentation
	pres.save("SwitchChartRowColumns_out.pptx", SaveFormat.Pptx);
} finally {
	if (pres != null) pres.dispose();
}

Disable the Vertical Axis for Line Charts

This Java code shows you how to hide the vertical axis for a line chart:

import com.aspose.slides.*;

Presentation pres = new Presentation();
try {
	IChart chart = pres.getSlides().get_Item(0).getShapes().addChart(ChartType.Line, 100, 100, 400, 300);
	chart.getAxes().getVerticalAxis().setVisible(false);

	pres.save("chart.pptx", SaveFormat.Pptx);
} finally {
	if (pres != null) pres.dispose();
}

Disable the Horizontal Axis for Line Charts

This code shows you how to hide the horizontal axis for a line chart:

import com.aspose.slides.*;

Presentation pres = new Presentation();
try {
	IChart chart = pres.getSlides().get_Item(0).getShapes().addChart(ChartType.Line, 100, 100, 400, 300);
	chart.getAxes().getHorizontalAxis().setVisible(false);

	pres.save("chart.pptx", SaveFormat.Pptx);
} finally {
	if (pres != null) pres.dispose();
}

Change a Category Axis

Using the CategoryAxisType property, you can specify your preferred category axis type (date or text). This code in Java demonstrates the operation:

import com.aspose.slides.*;

Presentation presentation = new Presentation("ExistingChart.pptx");
try {
	IChart chart = (IChart)presentation.getSlides().get_Item(0).getShapes().get_Item(0);
	chart.getAxes().getHorizontalAxis().setCategoryAxisType(CategoryAxisType.Date);
	chart.getAxes().getHorizontalAxis().setAutomaticMajorUnit(false);
	chart.getAxes().getHorizontalAxis().setMajorUnit(1);
	chart.getAxes().getHorizontalAxis().setMajorUnitScale(TimeUnitType.Months);
	presentation.save("ChangeChartCategoryAxis_out.pptx", SaveFormat.Pptx);
} finally {
	if (presentation != null) presentation.dispose();
}

Set the Date Format for Category Axis Values

Aspose.Slides for Android via Java allows you to set the date format for a category axis value. The operation is demonstrated in this Java code:

import com.aspose.slides.*;
import java.util.GregorianCalendar;

Presentation pres = new Presentation();
try {
    IChart chart = pres.getSlides().get_Item(0).getShapes().addChart(ChartType.Area, 50, 50, 450, 300);

    IChartDataWorkbook wb = chart.getChartData().getChartDataWorkbook();
    wb.clear(0);

    chart.getChartData().getCategories().clear();
    chart.getChartData().getSeries().clear();
    chart.getChartData().getCategories().add(wb.getCell(0, "A2", convertToOADate(new GregorianCalendar(2015, 1, 1))));
    chart.getChartData().getCategories().add(wb.getCell(0, "A3", convertToOADate(new GregorianCalendar(2016, 1, 1))));
    chart.getChartData().getCategories().add(wb.getCell(0, "A4", convertToOADate(new GregorianCalendar(2017, 1, 1))));
    chart.getChartData().getCategories().add(wb.getCell(0, "A5", convertToOADate(new GregorianCalendar(2018, 1, 1))));

    IChartSeries series = chart.getChartData().getSeries().add(ChartType.Line);
    series.getDataPoints().addDataPointForLineSeries(wb.getCell(0, "B2", 1));
    series.getDataPoints().addDataPointForLineSeries(wb.getCell(0, "B3", 2));
    series.getDataPoints().addDataPointForLineSeries(wb.getCell(0, "B4", 3));
    series.getDataPoints().addDataPointForLineSeries(wb.getCell(0, "B5", 4));
    chart.getAxes().getHorizontalAxis().setCategoryAxisType(CategoryAxisType.Date);
    chart.getAxes().getHorizontalAxis().setNumberFormatLinkedToSource(false);
    chart.getAxes().getHorizontalAxis().setNumberFormat("yyyy");
	
    pres.save("output.pptx", SaveFormat.Pptx);
} finally {
    if (pres != null) pres.dispose();
}

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.GregorianCalendar;
import java.util.concurrent.TimeUnit;

public static double convertToOADate(GregorianCalendar date) throws ParseException
{
    double oaDate;
    SimpleDateFormat myFormat = new SimpleDateFormat("dd MM yyyy");
    java.util.Date baseDate = myFormat.parse("30 12 1899");
    Long days = TimeUnit.DAYS.convert(date.getTimeInMillis() - baseDate.getTime(), TimeUnit.MILLISECONDS);
    oaDate = (double) days + ((double) date.get(Calendar.HOUR_OF_DAY) / 24) + ((double) date.get(Calendar.MINUTE) / (60 * 24)) + ((double) date.get(Calendar.SECOND) / (60 * 24 * 60));
    return oaDate;
}

Set a Rotation Angle for a Chart Axis Title

Aspose.Slides for Android via Java allows you to set the rotation angle for a chart axis title. This Java code demonstrates the operation:

import com.aspose.slides.*;

Presentation pres = new Presentation();
try {
    IChart chart = pres.getSlides().get_Item(0).getShapes().addChart(ChartType.ClusteredColumn, 50, 50, 450, 300);
    
    chart.getAxes().getVerticalAxis().setTitle(true);
    chart.getAxes().getVerticalAxis().getTitle().getTextFormat().getTextBlockFormat().setRotationAngle(90);

    pres.save("output.pptx", SaveFormat.Pptx);
} finally {
    if (pres != null) pres.dispose();
}

Set the Axis Position on a Category or Value Axis

Aspose.Slides for Android via Java allows you to set the position axis in a category or value axis. This Java code shows how to perform the task:

import com.aspose.slides.*;

Presentation pres = new Presentation();
try {
    IChart chart = pres.getSlides().get_Item(0).getShapes().addChart(ChartType.ClusteredColumn, 50, 50, 450, 300);
    
    chart.getAxes().getHorizontalAxis().setAxisBetweenCategories(true);

    pres.save("output.pptx", SaveFormat.Pptx);
} finally {
    if (pres != null) pres.dispose();
}

Set the Display Unit on a Chart Value Axis

Aspose.Slides for Android via Java allows you to set the display unit of a chart value axis. The axis then scales its tick labels by that unit: with DisplayUnitType.Millions, an axis that runs to 60,000,000 is labeled 0 to 60. This Java code demonstrates the operation:

import com.aspose.slides.*;

Presentation pres = new Presentation();
try {
    IChart chart = pres.getSlides().get_Item(0).getShapes().addChart(ChartType.ClusteredColumn, 50, 50, 450, 300);

    chart.getAxes().getVerticalAxis().setDisplayUnit(DisplayUnitType.Millions);
    
    pres.save("output.pptx", SaveFormat.Pptx);
} finally {
    if (pres != null) pres.dispose();
}

FAQ

How do I set the value at which one axis crosses the other (axis crossing)?

Axes provide a crossing setting: you can choose to cross at zero, at the maximum category/value, or at a specific numeric value. This is useful for shifting the X-axis up or down or for emphasizing a baseline.

How can I position tick labels relative to the axis (next to it, high, low)?

Set the tick label position to NextTo, High, Low, or None. This affects readability and helps conserve space, especially on small charts. The tick marks themselves are controlled separately by setMajorTickMark, which takes Cross, Inside, Outside, or None.