Skip to main content

MatrixHeat

Summary

The MatrixHeat class creates matrix heat charts. Matrix heat charts analyze relationships between two categorical fields, which can be visualized by count or summarized by a numeric field.

Learn more about matrix heat charts in ArcGIS Pro

Discussion

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

Syntax

MatrixHeat(x, y, {numberField}, {aggregation}, {nullPolicy}, {classificationMethod}, {classCount}, {timeBinningPropertiesCol}, {timeBinningPropertiesRow}, {title}, {description}, {xTitle}, {yTitle}, {dataSource}, {displaySize}, {theme})

Name Explanation Data type

x

The name of the field that determines the column categories.

String

y

The name of the field that determines the row categories.

String

numberField

(Optional)

The name of the field that is aggregated and used to determine the color of the chart cells.

String

aggregation

(Optional)

Specifies the statistical calculation that will be applied to values aggregated into each cell.

  • COUNT—The total number of records will be identified.

  • SUM—The sum of all values will be calculated.

  • MEAN—The mean of all values will be calculated.

  • MEDIAN—The median of all values will be calculated.

  • MIN—The minimum value will be identified.

  • MAX—The maximum value will be identified.

String

nullPolicy

(Optional)

Specifies how summarized cells returning a null value will be displayed.

  • null—Cells will be displayed as null.

  • zero—Cells will be displayed as zero.

String

classificationMethod

(Optional)

Specifies the classification method that will be used to visualize cell color and classify data.

  • equalIntervals—The equal interval method will be used.

  • geometricalIntervals—The geometric interval method will be used.

  • naturalBreaks—The natural breaks method will be used.

  • quantiles—The quantiles method will be used.

String

classCount

(Optional)

The number of classes used in the classification method.

Integer

timeBinningPropertiesCol

(Optional)

The time binning properties from the TimeBinningProperties class that are applied to the x-axis.

Object

timeBinningPropertiesRow

(Optional)

The time binning properties from the TimeBinningProperties class that are applied to the y-axis.

Object

title

(Optional)

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

(Optional)

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

String

xTitle

(Optional)

The title of the x-axis of the chart.

String

yTitle

(Optional)

The title of the y-axis of the chart.

String

dataSource

(Optional)

The data source of the chart. When a chart is exported using the exportToSVG method or displayed in ArcGIS Notebooks, 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

  • Apache Arrow table objects

  • Layer or Table objects

Object

displaySize

(Optional)

The size of the chart when exported using the exportToSVG method or displayed in ArcGIS Notebooks. 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

theme

(Optional)

Specifies the theme that will be applied to the chart.

  • Light—The Light theme will be applied.

  • Medium—The Medium theme will be applied.

  • Dark—The Dark theme will be applied.

String

Properties

Name Explanation Data type

aggregation

(Read and Write)

Specifies the statistical calculation that will be applied to values aggregated into each cell.

  • COUNT—The total number of records will be identified.

  • SUM—The sum of all values will be calculated.

  • MEAN—The mean of all values will be calculated.

  • MEDIAN—The median of all values will be calculated.

  • MIN—The minimum value will be identified.

  • MAX—The maximum value will be identified.

String

classCount

(Read and Write)

The number of classes that will be used in the classification method.

Integer

classificationMethod

(Read and Write)

Specifies the classification method that will be used to visualize cell color and classify data.

  • equalIntervals—The equal interval method will be used.

  • geometricalIntervals—The geometric interval method will be used.

  • naturalBreaks—The natural breaks method will be used.

  • quantiles—The quantiles method will be used.

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

  • Apache Arrow table objects

  • Layer or Table 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.

  • alignment—Specifies the alignment of the legend. Alignment options are left, bottom, top, and right.

  • title—The title of the legend.

  • visible—Specifies whether the legend will be displayed in the chart view. True displays the legend, and False hides the legend.

Object

nullPolicy

(Read and Write)

Specifies how summarized cells returning a null value will be displayed.

  • null—Cells will be displayed as null.

  • zero—Cells will be displayed as zero.

String

numberField

(Read and Write)

The name of the field that will be aggregated and used to determine the color of the chart cells.

String

theme

(Read and Write)

Specifies the theme that will be applied to the chart.

  • Light—The Light theme will be applied.

  • Medium—The Medium theme will be applied.

  • Dark—The Dark theme will be applied.

String

timeBinningPropertiesCol

(Read and Write)

The time binning properties from the TimeBinningProperties class that will be applied to the x-axis.

Object

timeBinningPropertiesRow

(Read and Write)

The time binning properties from the TimeBinningProperties class that will be applied to the y-axis.

Object

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 .

String

type

(Read only)

The string value indicating the chart type.

String

x

(Read and Write)

The name of the field that will determine the column categories.

String

xAxis

(Read and Write)

Specifies the properties of the x-axis.

  • field—The name of the field that will determine the column categories.

  • logarithmic—This property is not supported for the MatrixHeat class.

  • maximum—This property is not supported for the MatrixHeat class.

  • minimum—This property is not supported for the MatrixHeat class.

  • sort—The sorting method that will be applied to this axis. ASC is for ascending sorting and DESC is for descending sorting. A custom sort order can be specified by assigning a list of ordered category names.

  • title—The label of the axis that will display on the chart.

Object

y

(Read and Write)

The name of the field that will determine the row categories.

String

yAxis

(Read and Write)

Specifies the properties of the y-axis.

  • field—The name of the field that will determine the row categories. This property optionally accepts a two-item list in which the first item is the y-axis field and the second item is the numeric field that will be aggregated.

  • logarithmic—This property is not supported for the MatrixHeat class.

  • maximum—This property is not supported for the MatrixHeat class.

  • minimum—This property is not supported for the MatrixHeat class.

  • sort—The sorting method that will be applied to this axis. ASC is for ascending sorting and DESC is for descending sorting. A custom sort order can be specified by assigning a list of ordered category names.

  • title—The label of the axis that will display on the chart.

Object

Methods

addToLayer(layer_or_layerfile)

The addToLayer method adds the chart object to a layer or table view.

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

Name Explanation Data type

layer_or_layerfile

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

Object

Add a chart to an existing layer.

import arcpy

# Insert creation of chart object here
# ...

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)

exportToJPEG(path, width, height)

The exportToJPEG method exports a chart to JPEG format.

The chart is exported to a .jpg file that can be shared and viewed outside of ArcGIS Pro. JPEG is a raster image format that uses lossy compression to reduce file size.

Name Explanation Data type

path

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

String

width

The width of the output graphic.

Integer

height

The height of the output graphic.

Integer

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

import arcpy

# Insert creation of chart object here
# ...

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.exportToJPEG('theftsPerBeat.jpg', 800, 600)

exportToPNG(path, width, height)

The exportToPNG method exports a chart to PNG format.

The chart is exported to a .png file that can be shared and viewed outside of ArcGIS Pro. PNG is a raster image format that uses lossless compression to preserve image quality.

Name Explanation Data type

path

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

String

width

The width of the output graphic.

Integer

height

The height of the output graphic.

Integer

Access an existing chart from a layer, update the title, and export it to a .png file.

import arcpy

lyr = arcpy.mp.ArcGISProject('current').listLayers()[0]

# Retrieve the first chart belonging to the layer
chart = lyr.listCharts()[0]

# Update chart title
chart.title = 'Voter Turnout by State'

# Save the chart to PNG file with dimensions width=800, height=600
chart.exportToPNG('populationByState.png', 800, 600)

exportToSVG(path, width, height)

The exportToSVG method exports a chart to SVG format.

The chart is exported to an .svg file that can be shared and viewed outside of ArcGIS Pro. SVG is a vector image format that allows for editing and infinite scaling of the graphic without a loss in quality.

Name Explanation Data 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

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

import arcpy

# Insert creation of chart object here
# ...

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

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

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

updateChart()

The updateChart method updates chart properties to sync changes between the object and the chart previously added to a layer.

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

You can also modify the properties of the original chart instead of starting 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 allows 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.

import arcpy

# Insert creation of chart object here
# ...

chart.addToLayer(myLayer)

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

Code sample

Create a matrix heat chart using a .csv file and export the chart to an .svg file.

import arcpy
chart = arcpy.charts.MatrixHeat(x="OrigCity", y="DestCity", numberField="DelayTime",
                                aggregation="mean", title="Average Flight Arrival Delay",
                                displaySize=(800, 500), dataSource="flight_delays.csv")
chart.exportToSVG("matrix_heat_chart.svg")