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Line

In this topic

  1. Summary
  2. Discussion
  3. Syntax
  4. Properties
  5. Method Overview
  6. Methods
  7. Code sample

Summary

Line charts allow you to visualize change over a continuous range, such as time or distance. Visualizing change with a line chart allows for the overall trend to be displayed at once, and for multiple trends to be compared simultaneously.

Learn more about line charts in ArcGIS Pro

Discussion

When creating a chart object, optional arguments for the class constructor must be specified using the argument name; they cannot be specified by argument position. See the Code Samples section for an example of how to specify arguments using keywords.

Syntax

Line (x, {y}, {splitCategory}, {multiSeriesDisplay}, {miniChartsPerRow}, {showPreviewChart}, {aggregation}, {timeIntervalUnits}, {timeIntervalSize}, {timeAggregationType}, {trimIncompleteTimeInterval}, {nullPolicy}, {rotated}, {title}, {description}, {xTitle}, {yTitle}, {dataSource}, {displaySize})
ParameterExplanationData Type
x

The field name for the x-axis variable. The field must be a numeric or date field.

String
y

The field name or names for the y-axis variables. The value must be a numeric field or a list of numeric fields.

String
splitCategory

A categorical field that adds a separate series or line for each unique value in the field.

String
multiSeriesDisplay

Specifies the display type for a line chart with multiple series.

  • singleChart—All series are displayed in a single chart.
  • grid—The series are displayed as a grid of miniplots.
String
miniChartsPerRow

The number of minicharts that will be shown per row. The number of rows will be determined by the total number of series divided by the miniChartsPerRow value.

Integer
showPreviewChart

Specifies whether the preview chart will be displayed for grid charts.

  • True—The preview chart will be displayed.
  • False—The preview chart will not be displayed.

(The default value is False)

Boolean
aggregation

Specifies the statistical calculation that is applied to values aggregated into each temporal bin.

  • <None>—Each value is plotted on the chart regardless of overlap or recurring values.
  • COUNT—The total number of records is identified and applied.
  • SUM—The sum of all values is calculated and applied.
  • MEAN—The mean of all values is calculated and applied.
  • MEDIAN—The median of all values is identified and applied.
  • MIN—The minimum value is identified and applied.
  • MAX—The maximum value is identified and applied.
String
timeIntervalUnits

Specifies the time unit that corresponds to the timeIntervalSize.

  • SECONDS—The time unit is seconds.
  • MINUTES—The time unit is minutes.
  • HOURS—The time unit is hours.
  • DAYS—The time unit is days.
  • WEEKS—The time unit is weeks.
  • MONTHS—The time unit is months.
  • YEARS—The time unit is years.
String
timeIntervalSize

The span of time that is binned or aggregated together. This argument must be used in conjunction with timeIntervalUnits.

String
timeAggregationType

Specifies the time interval alignment type.

  • equalIntervalsFromStartTime—The time interval is aligned to the start date.
  • equalIntervalsFromEndTime—The time interval is aligned to the end date.
String
trimIncompleteTimeInterval

Specifies whether incomplete time intervals at the start or end of the data span (depending on the timeAggregationType value) are removed (trimmed) from the chart. Incomplete intervals on a chart can cause misleading results in which the period in question is underreported or overreported due to a different amount of time in the interval.

  • True—Incomplete intervals are removed.
  • False—Incomplete intervals are not removed.
String
nullPolicy

Specifies how summarized bins returning a null value are displayed.

  • null—Missing values are treated as null.
  • zero—Missing values are treated as zero.
  • interpolate—Interpolation is used to fill missing values.
String
rotated

Specifies whether lines are displayed horizontally or vertically.

  • True—Lines are displayed vertically.
  • False—Lines are displayed horizontally.

(The default value is False)

Boolean
title

The title of the chart. The title text appears at the top of the chart view and is used as the label for the chart in the Contents pane.

String
description

The description of the chart. The description text appears at the bottom of the chart view.

String
xTitle

The title of the x-axis of the chart.

String
yTitle

The title of the y-axis of the chart.

String
dataSource

The data source of the chart. When a chart is exported using the exportToSVG method or displayed in an ArcGIS Notebook, the data source will be read and rendered on the chart. Valid data sources include the following:

  • Paths to datasets, including local datasets, UNC paths, and service URLs
  • Arrow table objects
  • Layer objects

Object
displaySize
[displaySize,...]

The size of the chart when exported using the exportToSVG method or displayed in an ArcGIS Notebook. The value must be specified as a two-item list in which the first item is the width of the chart and the second item is the height of the chart.

List

Properties

PropertyExplanationData Type
aggregation
(Read and Write)

Specifies the statistical calculation that is applied to values aggregated into each temporal bin.

  • <None>—Each value is plotted on the chart regardless of overlap or recurring values.
  • COUNT—The total number of records is identified and applied.
  • SUM—The sum of all values is calculated and applied.
  • MEAN—The mean of all values is calculated and applied.
  • MEDIAN—The median of all values is identified and applied.
  • MIN—The minimum value is identified and applied.
  • MAX—The maximum value is identified and applied.
String
dataSource
(Read and Write)

The data source of the chart. When a chart is exported using the exportToSVG method or displayed in an ArcGIS Notebook, the data source will be read and rendered on the chart. Valid data sources include the following:

  • Paths to datasets, including local datasets, UNC paths, and service URLs
  • Arrow table objects
  • Layer objects.

Object
description
(Read and Write)

The description of the chart. The description text appears at the bottom of the chart view.

String
displaySize
(Read and Write)

The size of the chart when exported using the exportToSVG method or displayed in an ArcGIS Notebook. The value must be specified as a two-item list in which the first item is the width of the chart and the second item is the height of the chart.

List
legend
(Read and Write)

The properties of the chart legend.

  • visible—Specifies whether the legend will be displayed in the chart view. True displays the legend, and False hides the legend.
  • title—The title of the legend.
Object
miniChartsPerRow
(Read and Write)

The number of minicharts that will be shown per row. The number of rows will be determined by the total number of series divided by the miniChartsPerRow value.

Integer
multiSeriesDisplay
(Read and Write)

Specifies the display type for a line chart with multiple series.

  • singleChart—All series are displayed in a single chart.
  • grid—The series are displayed as a grid of miniplots.
String
nullPolicy
(Read and Write)

Specifies how summarized bins returning a null value are displayed.

  • null—Missing values are treated as null.
  • zero—Missing values are treated as zero.
  • interpolate—Interpolation is used to fill missing values.
String
rotated
(Read and Write)

Specifies whether the chart will be displayed vertically or horizontally.

  • True—The chart will be displayed horizontally.
  • False—The chart will be displayed vertically.
Boolean
showPreviewChart
(Read and Write)

Specifies whether the preview chart will be displayed for grid charts.

  • True—The preview chart will be displayed.
  • False—The preview chart will not be displayed.
Boolean
splitCategory
(Read and Write)

A categorical field that adds a separate series or line for each unique value in the field.

String
theme
(Read and Write)

Specifies the name of the theme that is applied to the chart.

String
timeAggregationType
(Read and Write)

Specifies the time interval alignment type.

  • equalIntervalsFromStartTime—The time interval is aligned to the start date.
  • equalIntervalsFromEndTime—The time interval is aligned to the end date.
String
timeIntervalSize
(Read and Write)

The span of time that is binned or aggregated together. The property must be used in conjunction with timeIntervalUnits.

String
timeIntervalUnits
(Read and Write)

Specifies the time unit that corresponds to the timeIntervalSize value.

  • SECONDS—The time unit is seconds.
  • MINUTES—The time unit is minutes.
  • HOURS—The time unit is hours.
  • DAYS—The time unit is days.
  • WEEKS—The time unit is weeks.
  • MONTHS—The time unit is months.
  • YEARS—The time unit is years.
String
title
(Read and Write)

The title of the chart. The title text appears at the top of the chart view and is used as the label in the Contents pane on the List By Drawing Order tab List By Drawing Order.

String
trimIncompleteTimeInterval
(Read and Write)

Specifies whether incomplete time intervals at the start or end of the data span (depending on the timeAggregationType value) are removed (trimmed) from the chart. Incomplete intervals on a chart can cause misleading results in which the period in question is underreported or overreported due to a different amount of time in the interval.

  • True—Incomplete intervals are removed.
  • False—Incomplete intervals are not removed.
String
type
(Read Only)

The string value indicating the chart type.

String
x
(Read and Write)

The field name for the x-axis variable. The field must be a numeric or date field.

String
xAxis
(Read and Write)

Sets the properties of the x-axis.

  • field—The field name for the x-axis variable. The field must be a numeric or date field.
  • logarithmic—Specifies whether the axis is logarithmic. True displays the logarithmic axis. False displays the linear axis.
  • maximum—The maximum axis bound.
  • minimum—The minimum axis bound.
  • sort—This property is not supported for the Line class.
  • title—The label of the axis that displays on the chart.
Object
y
(Read and Write)

The field name or names for the numeric field or fields. Provide a single field name or a list of field names.

String
yAxis
(Read and Write)

Sets the properties of the y-axis.

  • field—The field name or names for the numeric field or fields. Provide a single field name or a list of field names.
  • invert—Specifies whether the axis is inverted. True inverts the axis, and False does not invert the axis.
  • logarithmic—Specifies whether the axis is logarithmic. True displays a logarithmic axis. False displays a linear axis.
  • maximum—The maximum axis bound.
  • minimum—The minimum axis bound.
  • sort—This property is not supported for the Line class.
  • title—The label of the axis that displays on the chart.
  • useAdaptiveBounds—Specifies whether a grid chart displays with adaptive or fixed axis bounds. True displays the axis with adaptive bounds. False displays the axis with fixed bounds.
Object

Method Overview

MethodExplanation
addToLayer (layer_or_layerfile)

Adds the chart object to a layer or stand-alone table.

exportToSVG (path, width, height)

Exports the chart to SVG format.

updateChart ()

Updates chart properties to sync changes between the object and the chart previously added to a layer.

Methods

addToLayer (layer_or_layerfile)
ParameterExplanationData Type
layer_or_layerfile

The chart will be added to the target object. The layer_or_layerfile argument can be a Layer or a Table object.

Object

Often the final step after defining chart properties is to add the chart object to a layer or table using the addToLayer method.

Add a chart to an existing layer.

import arcpy

aprx = arcpy.mp.ArcGISProject("current")
map = aprx.listMaps()[0]
censusLayer = map.listLayers('Census Block Groups')[0]

# Add chart object to a layer
chart.addToLayer(censusLayer)
exportToSVG (path, width, height)
ParameterExplanationData Type
path

The path where the chart will be exported in SVG format.

String
width

The width of the output graphic.

Integer
height

The height of the output graphic.

Integer

In some cases, you may want to save the chart as a graphic that can be shared and viewed outside of ArcGIS Pro. Exporting to the SVG graphic format is beneficial, as the chart elements and text are stored as vector elements that can be independently modified in a vector graphics software. An SVG graphic can also be resized to any scale without pixelation or loss in quality.

Export a chart that has a project layer data source to an .svg file.

import arcpy

aprx = arcpy.mp.ArcGISProject('current')
censusLayer = aprx.listMaps()[0].listLayers('Census Block Groups')[0]

# Set data source of chart object to a layer within current project
chart.dataSource = censusLayer

# Save the chart to file with dimensions width=500, height=500
chart.exportToSVG('populationByState.svg', 500, 500)

Export a chart that has a feature service data source to an .svg file.


featureServiceURL = r'https://services1.arcgis.com/hLJbHVT9ZrDIzK0I/arcgis/rest/services/CrimesChiTheft/FeatureServer/0'

# Set data source of chart object to a feature service URL
chart.dataSource = featureServiceURL

# Save the chart to file with dimensions width=800, height=600
chart.exportToSVG('theftsPerBeat.svg', 800, 600)
updateChart ()

Often the final step after defining chart properties is to add the chart object to a layer using the addToLayer method.

To further modify the chart properties, you can modify the properties of the original chart instead of starting from scratch with a new chart. You can then use the updateChart method to synchronize any changes into the chart that was added to the layer. This will allow the changes you make to be presented in the Chart properties pane and chart view.

Use the updateChart method to synchronize chart property changes into a layer.


chart.addToLayer(myLayer)

# Further modification is necessary
chart.description = "Data from the U.S. Census Bureau"
chart.updateChart()

Code sample

Create a line chart and add it to a layer in the current project.

import arcpy

lyr = arcpy.mp.ArcGISProject("current").listMaps()[0].listLayers()[0]
chart = arcpy.charts.Line(x="date", y="aqi", aggregation="mean")
chart.addToLayer(lyr)

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In this topic
  1. Summary
  2. Discussion
  3. Syntax
  4. Properties
  5. Method Overview
  6. Methods
  7. Code sample