# Customize Chart Axes in Presentations Using Python

> Discover how to use Aspose.Slides for Python via Java to customize chart axes in PowerPoint presentations for reports and visualizations.

Source: https://docs.aspose.com/slides/python-java/chart-axis/
Updated: 2026-09-10


## **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 Maximum Values on the Vertical Axis of a Chart**

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

1. Create an instance of the [Presentation](https://reference.aspose.com/slides/python-java/aspose.slides/presentation/) class.
1. Access the first slide.
1. Add a chart with default data.
1. Get the actual maximum value on the axis.
1. Get the actual minimum value on the axis.
1. Get the actual major unit of the axis.
1. Get the actual minor unit of the axis.
1. Get the actual major unit scale of the axis.
1. 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 Python:

```python
import jpype
import asposeslides

if not jpype.isJVMStarted():
    jpype.startJVM()

from asposeslides.api import Presentation, ChartType, SaveFormat

presentation = Presentation()
try:
    chart = presentation.getSlides().get_Item(0).getShapes().addChart(ChartType.Area, 100, 100, 500, 350)
    chart.validateChartLayout()

    max_value = chart.getAxes().getVerticalAxis().getActualMaxValue()
    min_value = chart.getAxes().getVerticalAxis().getActualMinValue()

    major_unit = chart.getAxes().getVerticalAxis().getActualMajorUnit()
    minor_unit = chart.getAxes().getVerticalAxis().getActualMinorUnit()

    major_unit_scale = chart.getAxes().getVerticalAxis().getActualMajorUnitScale()
    minor_unit_scale = chart.getAxes().getVerticalAxis().getActualMinorUnitScale()

    # Saves the presentation
    presentation.save("MaxValuesVerticalAxis_out.pptx", SaveFormat.Pptx)
finally:
    presentation.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 Python code shows you how to perform the data swap task between axes on a chart:

```python
import jpype
import asposeslides

if not jpype.isJVMStarted():
    jpype.startJVM()

from asposeslides.api import Presentation, ChartType, SaveFormat

presentation = Presentation()
try:
    chart = presentation.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
    workbook = chart.getChartData().getChartDataWorkbook()

    # Switches rows and columns
    chart.getChartData().switchRowColumn()

    # Saves presentation
    presentation.save("SwitchChartRowColumns_out.pptx", SaveFormat.Pptx)
finally:
    presentation.dispose()
```

## **Disable the Vertical Axis for Line Charts**

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

```python
import jpype
import asposeslides

if not jpype.isJVMStarted():
    jpype.startJVM()

from asposeslides.api import Presentation, ChartType, SaveFormat

presentation = Presentation()
try:
    chart = presentation.getSlides().get_Item(0).getShapes().addChart(ChartType.Line, 100, 100, 400, 300)
    chart.getAxes().getVerticalAxis().setVisible(False)

    presentation.save("chart.pptx", SaveFormat.Pptx)
finally:
    presentation.dispose()
```

## **Disable the Horizontal Axis for Line Charts**

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

```python
import jpype
import asposeslides

if not jpype.isJVMStarted():
    jpype.startJVM()

from asposeslides.api import Presentation, ChartType, SaveFormat

presentation = Presentation()
try:
    chart = presentation.getSlides().get_Item(0).getShapes().addChart(ChartType.Line, 100, 100, 400, 300)
    chart.getAxes().getHorizontalAxis().setVisible(False)

    presentation.save("chart.pptx", SaveFormat.Pptx)
finally:
    presentation.dispose()
```

## **Change a Category Axis**

Using the [setCategoryAxisType](https://reference.aspose.com/slides/python-java/aspose.slides/axis/#setCategoryAxisType) method, you can specify your preferred category axis type (**date** or **text**). This code in Python demonstrates the operation:

```python
import jpype
import asposeslides

if not jpype.isJVMStarted():
    jpype.startJVM()

from asposeslides.api import Presentation, Chart, SaveFormat, CategoryAxisType, TimeUnitType

presentation = Presentation("ExistingChart.pptx")
try:
    if presentation.getSlides().size() > 0 and presentation.getSlides().get_Item(0).getShapes().size() > 0:
        chart = presentation.getSlides().get_Item(0).getShapes().get_Item(0)
        if isinstance(chart, Chart):
            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)
        else:
            print("The first shape is not a chart.")
    else:
        print("The presentation has no first shape to update.")
finally:
    presentation.dispose()
```

## **Set the Date Format for Category Axis Values**

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

```python
import jpype
import asposeslides

if not jpype.isJVMStarted():
    jpype.startJVM()

from asposeslides.api import Presentation, ChartType, SaveFormat, CategoryAxisType

from datetime import datetime

def convert_to_oa_date(date):
    base_date = datetime(1899, 12, 30)
    return (date - base_date).total_seconds() / 86400


presentation = Presentation()
try:
    chart = presentation.getSlides().get_Item(0).getShapes().addChart(ChartType.Area, 50, 50, 450, 300)

    workbook = chart.getChartData().getChartDataWorkbook()
    workbook.clear(0)

    chart.getChartData().getCategories().clear()
    chart.getChartData().getSeries().clear()
    category_date = datetime(2015, 2, 1)
    category_value = convert_to_oa_date(category_date)
    category_cell = workbook.getCell(0, "A2", category_value)
    chart.getChartData().getCategories().add(category_cell)
    category_date = datetime(2016, 2, 1)
    category_value = convert_to_oa_date(category_date)
    category_cell = workbook.getCell(0, "A3", category_value)
    chart.getChartData().getCategories().add(category_cell)
    category_date = datetime(2017, 2, 1)
    category_value = convert_to_oa_date(category_date)
    category_cell = workbook.getCell(0, "A4", category_value)
    chart.getChartData().getCategories().add(category_cell)
    category_date = datetime(2018, 2, 1)
    category_value = convert_to_oa_date(category_date)
    category_cell = workbook.getCell(0, "A5", category_value)
    chart.getChartData().getCategories().add(category_cell)

    series = chart.getChartData().getSeries().add(ChartType.Line)
    value_cell = workbook.getCell(0, "B2", 1.0)
    series.getDataPoints().addDataPointForLineSeries(value_cell)
    value_cell = workbook.getCell(0, "B3", 2.0)
    series.getDataPoints().addDataPointForLineSeries(value_cell)
    value_cell = workbook.getCell(0, "B4", 3.0)
    series.getDataPoints().addDataPointForLineSeries(value_cell)
    value_cell = workbook.getCell(0, "B5", 4.0)
    series.getDataPoints().addDataPointForLineSeries(value_cell)
    chart.getAxes().getHorizontalAxis().setCategoryAxisType(CategoryAxisType.Date)
    chart.getAxes().getHorizontalAxis().setNumberFormatLinkedToSource(False)
    chart.getAxes().getHorizontalAxis().setNumberFormat("yyyy")

    presentation.save("output.pptx", SaveFormat.Pptx)
finally:
    presentation.dispose()
```

## **Set a Rotation Angle for a Chart Axis Title**

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

```python
import jpype
import asposeslides

if not jpype.isJVMStarted():
    jpype.startJVM()

from asposeslides.api import Presentation, ChartType, SaveFormat

presentation = Presentation()
try:
    chart = presentation.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)

    presentation.save("output.pptx", SaveFormat.Pptx)
finally:
    presentation.dispose()
```

## **Set the Axis Position on a Category or Value Axis**

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

```python
import jpype
import asposeslides

if not jpype.isJVMStarted():
    jpype.startJVM()

from asposeslides.api import Presentation, ChartType, SaveFormat

presentation = Presentation()
try:
    chart = presentation.getSlides().get_Item(0).getShapes().addChart(ChartType.ClusteredColumn, 50, 50, 450, 300)

    chart.getAxes().getHorizontalAxis().setAxisBetweenCategories(True)

    presentation.save("output.pptx", SaveFormat.Pptx)
finally:
    presentation.dispose()
```

## **Set the Display Unit on a Chart Value Axis**

Aspose.Slides for Python 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](https://reference.aspose.com/slides/python-java/aspose.slides/displayunittype/#Millions), an axis that runs to 60,000,000 is labeled 0 to 60. This Python code demonstrates the operation:

```python
import jpype
import asposeslides

if not jpype.isJVMStarted():
    jpype.startJVM()

from asposeslides.api import Presentation, ChartType, SaveFormat, DisplayUnitType

presentation = Presentation()
try:
    chart = presentation.getSlides().get_Item(0).getShapes().addChart(ChartType.ClusteredColumn, 50, 50, 450, 300)

    chart.getAxes().getVerticalAxis().setDisplayUnit(DisplayUnitType.Millions)

    presentation.save("output.pptx", SaveFormat.Pptx)
finally:
    presentation.dispose()
```

## **FAQ**

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

Axes provide a [crossing setting](https://reference.aspose.com/slides/python-java/aspose.slides/axis/#setCrossType): 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 marks relative to the axis (crossing, outside, inside)?**

Set the [tick mark position](https://reference.aspose.com/slides/python-java/aspose.slides/axis/#setMajorTickMark) to "cross", "outside", or "inside". This affects readability and helps conserve space, especially on small charts.