ChartDataLabelLocationMode enumeration

ChartDataLabelLocationMode enumeration

Specifies how the values ​​that specify the location of a data label - the ChartDataLabel.left and ChartDataLabel.top properties - are interpreted.

Members

Name	Description
OFFSET	The location of a data label is specified by an offset from the position defined by its ChartDataLabel.position property.
ABSOLUTE	The location of a data label is specified using absolute coordinates, staring from the upper left corner of a chart.

Examples

Shows how to place data labels of doughnut chart outside doughnut.

doc = aw.Document()
builder = aw.DocumentBuilder(doc=doc)
chart_width = 432
chart_height = 252
shape = builder.insert_chart(chart_type=aw.drawing.charts.ChartType.DOUGHNUT, width=chart_width, height=chart_height)
chart = shape.chart
series_coll = chart.series
# Delete default generated series.
series_coll.clear()
# Hide the legend.
chart.legend.position = aw.drawing.charts.LegendPosition.NONE
# Generate data.
data_length = 20
total_value = 0
categories = [None for i in range(0, data_length)]
values = [None for i in range(0, data_length)]
i = 0
while i < data_length:
    categories[i] = f'Category {i}'
    values[i] = data_length - i
    total_value = total_value + values[i]
    i += 1
series = series_coll.add(series_name='Series 1', categories=categories, values=values)
series.has_data_labels = True
data_labels = series.data_labels
data_labels.show_value = True
data_labels.show_leader_lines = True
# The Position property cannot be used for doughnut charts. Let's place data labels using the Left and Top
# properties around a circle outside of the chart doughnut.
# The origin is in the upper left corner of the chart.
title_area_height = 25.5  # This can be calculated using title text and font.
doughnut_center_y = title_area_height + (chart_height - title_area_height) / 2
doughnut_center_x = chart_width / 2
label_height = 16.5  # This can be calculated using label font.
one_char_label_width = 12.75  # This can be calculated for each label using its text and font.
two_char_label_width = 17.25  # This can be calculated for each label using its text and font.
y_margin = 0.75
label_margin = 1.5
label_circle_radius = chart_height - doughnut_center_y - y_margin - label_height / 2
# Because the data points start at the top, the X coordinates used in the Left and Top properties of
# the data labels point to the right and the Y coordinates point down, the starting angle is -PI/2.
total_angle = -math.pi / 2
previous_label = None
i = 0
while i < series.y_values.count:
    data_label = data_labels[i]
    value = series.y_values[i].double_value
    label_width = None
    if value < 10:
        label_width = one_char_label_width
    else:
        label_width = two_char_label_width
    label_segment_angle = value / total_value * 2 * math.pi
    label_angle = label_segment_angle / 2 + total_angle
    label_center_x = label_circle_radius * math.cos(label_angle) + doughnut_center_x
    label_center_y = label_circle_radius * math.sin(label_angle) + doughnut_center_y
    label_left = label_center_x - label_width / 2
    label_top = label_center_y - label_height / 2
    # If the current data label overlaps other labels, move it horizontally.
    if previous_label != None and math.fabs(previous_label.top - label_top) < label_height and (math.fabs(previous_label.left - label_left) < label_width):
        # Move right on the top, left on the bottom.
        is_on_top = total_angle < 0 or total_angle >= math.pi
        factor = None
        if is_on_top:
            factor = 1
        else:
            factor = -1
        label_left = previous_label.left + label_width * factor + label_margin
    data_label.left = label_left
    data_label.left_mode = aw.drawing.charts.ChartDataLabelLocationMode.ABSOLUTE
    data_label.top = label_top
    data_label.top_mode = aw.drawing.charts.ChartDataLabelLocationMode.ABSOLUTE
    total_angle = total_angle + label_segment_angle
    previous_label = data_label
    i += 1
doc.save(file_name=ARTIFACTS_DIR + 'Charts.DoughnutChartLabelPosition.docx')

See Also

• module aspose.words.drawing.charts