Chart Data Label
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Data labels on a chart show details about the chart data series or individual data points. They allow readers to quickly identify data series and they also make charts easier to understand.
Set Precision of Data in Chart Data Labels
This Python code shows you how to set the data precision in a chart data label:
import aspose.slides.charts as charts
import aspose.slides as slides
with slides.Presentation() as pres:
chart = pres.slides[0].shapes.add_chart(charts.ChartType.LINE, 50, 50, 450, 300)
chart.has_data_table = True
chart.chart_data.series[0].number_format_of_values = "#,##0.00"
pres.save("PrecisionOfDatalabels_out.pptx", slides.export.SaveFormat.PPTX)
Display Percentage as Labels
Aspose.Slides for Python via .NET allows you to set percentage labels on displayed charts. This Python code demonstrates the operation:
import aspose.slides.charts as charts
import aspose.slides as slides
# Creates an instance of the Presentation class
with slides.Presentation() as presentation:
slide = presentation.slides[0]
chart = slide.shapes.add_chart(charts.ChartType.STACKED_COLUMN, 20, 20, 400, 400)
series = chart.chart_data.series[0]
total_for_Cat = [0]*len(chart.chart_data.categories)
for k in range(len(chart.chart_data.categories)):
cat = chart.chart_data.categories[k]
for i in range(len(chart.chart_data.series)):
total_for_Cat[k] += chart.chart_data.series[i].data_points[k].value.data
dataPontPercent = 0
for x in range(len(chart.chart_data.series)):
series = chart.chart_data.series[x]
series.labels.default_data_label_format.show_legend_key = False
for j in range(len(series.data_points)):
lbl = series.data_points[j].label
dataPontPercent = series.data_points[j].value.data / total_for_Cat[j] * 100
port = slides.Portion()
port.text = "{0:.2f} %".format(dataPontPercent)
port.portion_format.font_height = 8
lbl.text_frame_for_overriding.text = ""
para = lbl.text_frame_for_overriding.paragraphs[0]
para.portions.add(port)
lbl.data_label_format.show_series_name = False
lbl.data_label_format.show_percentage = False
lbl.data_label_format.show_legend_key = False
lbl.data_label_format.show_category_name = False
lbl.data_label_format.show_bubble_size = False
# Saves the presentation containing the chart
presentation.save("DisplayPercentageAsLabels_out.pptx", slides.export.SaveFormat.PPTX)
Set Percentage Sign with Chart Data Labels
This Python code shows you to set the percentage sign for a chart data label:
import aspose.slides.charts as charts
import aspose.slides as slides
import aspose.pydrawing as draw
# Creates an instance of Presentation class
with slides.Presentation() as presentation:
# Gets a slide's reference through its index
slide = presentation.slides[0]
# Creates the PercentsStackedColumn chart on a slide
chart = slide.shapes.add_chart(charts.ChartType.PERCENTS_STACKED_COLUMN, 20, 20, 500, 400)
# Sets the NumberFormatLinkedToSource to false
chart.axes.vertical_axis.is_number_format_linked_to_source = False
chart.axes.vertical_axis.number_format = "0.00%"
chart.chart_data.series.clear()
defaultWorksheetIndex = 0
# Gets the chart data worksheet
workbook = chart.chart_data.chart_data_workbook
# Adds new series
series = chart.chart_data.series.add(workbook.get_cell(defaultWorksheetIndex, 0, 1, "Reds"), chart.type)
series.data_points.add_data_point_for_bar_series(workbook.get_cell(defaultWorksheetIndex, 1, 1, 0.30))
series.data_points.add_data_point_for_bar_series(workbook.get_cell(defaultWorksheetIndex, 2, 1, 0.50))
series.data_points.add_data_point_for_bar_series(workbook.get_cell(defaultWorksheetIndex, 3, 1, 0.80))
series.data_points.add_data_point_for_bar_series(workbook.get_cell(defaultWorksheetIndex, 4, 1, 0.65))
# Sets the fill color of series
series.format.fill.fill_type = slides.FillType.SOLID
series.format.fill.solid_fill_color.color = draw.Color.red
# Sets the LabelFormat properties
series.labels.default_data_label_format.show_value = True
series.labels.default_data_label_format.is_number_format_linked_to_source = False
series.labels.default_data_label_format.number_format = "0.0%"
series.labels.default_data_label_format.text_format.portion_format.font_height = 10
series.labels.default_data_label_format.text_format.portion_format.fill_format.fill_type = slides.FillType.SOLID
series.labels.default_data_label_format.text_format.portion_format.fill_format.solid_fill_color.color = draw.Color.white
series.labels.default_data_label_format.show_value = True
# Adds new series
series2 = chart.chart_data.series.add(workbook.get_cell(defaultWorksheetIndex, 0, 2, "Blues"), chart.type)
series2.data_points.add_data_point_for_bar_series(workbook.get_cell(defaultWorksheetIndex, 1, 2, 0.70))
series2.data_points.add_data_point_for_bar_series(workbook.get_cell(defaultWorksheetIndex, 2, 2, 0.50))
series2.data_points.add_data_point_for_bar_series(workbook.get_cell(defaultWorksheetIndex, 3, 2, 0.20))
series2.data_points.add_data_point_for_bar_series(workbook.get_cell(defaultWorksheetIndex, 4, 2, 0.35))
# Sets Fill type and color
series2.format.fill.fill_type = slides.FillType.SOLID
series2.format.fill.solid_fill_color.color = draw.Color.blue
series2.labels.default_data_label_format.show_value = True
series2.labels.default_data_label_format.is_number_format_linked_to_source = False
series2.labels.default_data_label_format.number_format = "0.0%"
series2.labels.default_data_label_format.text_format.portion_format.font_height = 10
series2.labels.default_data_label_format.text_format.portion_format.fill_format.fill_type = slides.FillType.SOLID
series2.labels.default_data_label_format.text_format.portion_format.fill_format.solid_fill_color.color = draw.Color.white
# Writes the presentation to disk
presentation.save("SetDatalabelsPercentageSign_out.pptx", slides.export.SaveFormat.PPTX)
Set Label Distance From Axis
This Python code shows you how to set the label distance from a category axis when you are dealing with a chart plotted from axes:
import aspose.slides.charts as charts
import aspose.slides as slides
# Creates an instance of the Presentation class
with slides.Presentation() as presentation:
# Gets a slide's reference
sld = presentation.slides[0]
# Creates a chart on the slide
ch = sld.shapes.add_chart(charts.ChartType.CLUSTERED_COLUMN, 20, 20, 500, 300)
# Sets the label distance from an axis
ch.axes.horizontal_axis.label_offset = 500
# Writes the presentation to disk
presentation.save("SetCategoryAxisLabelDistance_out.pptx", slides.export.SaveFormat.PPTX)
Adjust Label Location
When you create a chart that does not rely on any axis such as a pie chart, the chart’s data labels may end up being too close to its edge. In such a case, you have to adjust the location of the data label so that the leader lines get displayed clearly.
This Python code shows you how to adjust the label location on a pie chart:
import aspose.slides as slides
with slides.Presentation() as pres:
chart = pres.slides[0].shapes.add_chart(slides.charts.ChartType.PIE, 50, 50, 200, 200)
series = chart.chart_data.series
label = series[0].labels[0]
label.data_label_format.show_value = True
label.data_label_format.position = slides.charts.LegendDataLabelPosition.OUTSIDE_END
label.x = 0.71
label.y = 0.04
pres.save("pres.pptx", slides.export.SaveFormat.PPTX)
