Histogram

Synthèse

The Histogram class creates histograms. Histograms visually summarize the distribution of a continuous numeric variable by measuring the frequency at which certain values appear in the dataset.

Learn more about histograms in ArcGIS AllSource

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.

Syntaxe

Histogram (x, {splitCategory}, {miniChartsPerRow}, {showPreviewChart}, {binCount}, {showMean}, {showMedian}, {showStandardDeviation}, {showComparisonDistribution}, {dataTransformationType}, {dataTransformationParameters}, {title}, {description}, {xTitle}, {yTitle}, {dataSource}, {displaySize}, {theme})
ParamètreExplicationType de données
x

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

String
splitCategory

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

String
miniChartsPerRow

The number of mini charts that will be shown per row.

Integer
showPreviewChart

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

  • TrueThe preview chart will be displayed.
  • FalseThe preview chart will not be displayed.

(La valeur par défaut est False)

Boolean
binCount

The number of bins to display in the histogram.

Integer
showMean

Specifies whether the mean statistical line is visible in the histogram.

  • TrueThe mean line is visible in the histogram.
  • FalseThe mean line is not visible in the histogram.
Boolean
showMedian

Specifies whether the median statistical line is visible in the histogram.

  • TrueThe median line is visible in the histogram.
  • FalseThe median line is not visible in the histogram.
Boolean
showStandardDeviation

Specifies whether the standard deviation lines are visible in the histogram.

  • TrueThe standard deviation lines are visible in the histogram.
  • FalseThe standard deviation lines are not visible in the histogram.
Boolean
showComparisonDistribution

Specifies whether the normal distribution comparison line is visible in the histogram.

  • TrueThe comparison line is visible in the histogram.
  • FalseThe comparison line is not visible in the histogram.
Boolean
dataTransformationType

Specifies the data transformation type.

  • noneNo transformation is applied.
  • logarithmicA logarithmic transformation is applied.
  • squareRootA square root transformation is applied.
  • inverseAn inverse transformation is applied.
  • boxCoxA box-cox transformation is applied.
String
dataTransformationParameters

The data transformation parameters for the Box-Cox transformation. This parameter accepts a two-item list in which the first item is the power parameter and the second item is the shift parameter.

List
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 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
[displaySize,...]

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

Specifies the theme that will be applied to the chart.

  • LightThe Light theme will be applied.
  • MediumThe Medium theme will be applied.
  • DarkThe Dark theme will be applied.
String

Propriétés

PropriétéExplicationType de données
binCount
(Lecture et écriture)

The number of bins that will be displayed in the histogram.

Integer
MISSING_PROPNAME
(Lecture et écriture)
List
dataSource
(Lecture et écriture)

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 or Table objects

Object
dataTransformationParameters
(Lecture et écriture)

The data transformation parameters for the Box-Cox transformation. This parameter accepts a two-item list where the first item is the power parameter and the second item is the shift parameter.

List
dataTransformationType
(Lecture et écriture)

Specifies the data transformation type.

  • noneNo transformation will be applied.
  • logarithmicA logarithmic transformation will be applied.
  • squareRootA square root transformation will be applied.
  • inverseAn inverse transformation will be applied.
  • boxCoxA box-cox transformation will be applied.
String
description
(Lecture et écriture)

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

String
displaySize
(Lecture et écriture)

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
MISSING_PROPNAME
(Lecture et écriture)
Boolean
legend
(Lecture et écriture)

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
miniChartsPerRow
(Lecture et écriture)

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
showComparisonDistribution
(Lecture et écriture)

Specifies whether the normal distribution comparison line will be visible in the histogram.

  • TrueThe comparison line will be visible in the histogram.
  • FalseThe comparison line will not be not visible in the histogram.
Boolean
showMean
(Lecture et écriture)

Specifies whether the mean statistical line will be visible in the histogram.

  • TrueThe mean line will be visible in the histogram.
  • FalseThe mean line will not be visible in the histogram.
Boolean
showMedian
(Lecture et écriture)

Specifies whether the median statistical line will be visible in the histogram.

  • TrueThe median line will be visible in the histogram.
  • FalseThe median line will not be visible in the histogram.
Boolean
showPreviewChart
(Lecture et écriture)

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

  • TrueThe preview chart will be displayed.
  • FalseThe preview chart will not be displayed.
Boolean
showStandardDeviation
(Lecture et écriture)

Specifies whether the standard deviation lines will be visible in the histogram.

  • TrueThe standard deviation lines will be visible in the histogram.
  • FalseThe standard deviation lines will not be visible in the histogram.
Boolean
splitCategory
(Lecture et écriture)

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

String
theme
(Lecture et écriture)

The name of the theme that will be applied to the chart.

String
title
(Lecture et écriture)

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 Répertorier par ordre d'affichage.

String
type
(Lecture seule)

The string value indicating the chart type.

String
x
(Lecture et écriture)

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

String
xAxis
(Lecture et écriture)

Specifies the properties of the x-axis.

  • addGuide—Adds a guide to the axis using a Guide object.
  • field—The field name for the x-axis variable. The field must be a numeric field.
  • logarithmic—This property is not supported for the Histogram class.
  • listGuides—A list of Guide objects for the axis.
  • maximum—The maximum axis bound.
  • minimum—The minimum axis bound.
  • removeGuide—Removes the guide specified by the Guide object argument.
  • sort—This property is not supported for the Histogram 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
yAxis
(Lecture et écriture)

Specifies the properties of the y-axis.

  • addGuide—Adds a guide to the axis using a Guide object.
  • field—This property is not supported for the Histogram class.
  • logarithmic—This property is not supported for the Histogram class.
  • listGuides—A list of Guide objects for the axis.
  • maximum—The maximum axis bound.
  • minimum—The minimum axis bound.
  • removeGuide—Removes the guide specified by the Guide object argument.
  • sort—This property is not supported for the Histogram 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

Vue d’ensemble des méthodes

MéthodeExplication
addToLayer (layer_or_layerfile)

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

exportToSVG (path, width, height)

The exportToSVG method exports the chart to SVG format.

updateChart ()

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

Méthodes

addToLayer (layer_or_layerfile)
ParamètreExplicationType de données
layer_or_layerfile

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

Object

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

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)
exportToSVG (path, width, height)
ParamètreExplicationType de données
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 AllSource. 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 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

# 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)

Export a chart that has a feature service data source to an .svg 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.exportToSVG('theftsPerBeat.svg', 800, 600)
updateChart ()

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()

Exemple de code

Create a histogram using a layer name as the data source and export the histogram to an .svg file.

import arcpy

chart = arcpy.charts.Histogram("price", binCount=20, showMedian=True)																											
chart.dataSource = "airbnb_listings"
chart.title = "Distribution of AirBnB Listing Price"
chart.exportToSVG("histogram.svg", width=1000, height=800)