Synthèse
Bar charts summarize and compare categorical data using proportional bar lengths to represent values.
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.
Syntaxe
Bar (x, {y}, {aggregation}, {splitCategory}, {multiSeriesDisplay}, {miniChartsPerRow}, {showPreviewChart}, {showMovingAverage}, {movingAveragePeriod}, {timeBinningProperties}, {rotated}, {title}, {description}, {xTitle}, {yTitle}, {dataSource}, {displaySize})
Paramètre | Explication | Type de données |
x | The field name for the x-axis variable. The field must be a category or a date field. If an empty string is specified, the chart will match the layer symbology. | String |
y | The field names for the numeric fields. Provide a single field name or a list of field names. | String |
aggregation | Specifies the statistical calculation that will be applied to values that occur at the same value along the x-axis.
| String |
splitCategory | A second categorical field that adds a separate series or bar for each unique value in the field. | String |
multiSeriesDisplay | Specifies the display type for a bar chart with multiple series.
| 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.
(La valeur par défaut est False) | Boolean |
showMovingAverage | Specifies whether the moving average line will be displayed for temporal bar charts.
(La valeur par défaut est False) | Boolean |
movingAveragePeriod | The size of the moving average period. | Integer |
timeBinningProperties | The time binning properties from the TimeBinningProperties class. | Object |
rotated | Specifies whether bars will be displayed vertically or horizontally.
(La valeur par défaut est 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:
| 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 |
Propriétés
Propriété | Explication | Type de données |
aggregation (Lecture et écriture) | Specifies the statistical calculation that is applied to values that occur at the same value along the x-axis.
| String |
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:
| Object |
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 |
legend (Lecture et écriture) | The properties of the chart 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 |
movingAveragePeriod (Lecture et écriture) | The size of the moving average period. | Integer |
multiSeriesDisplay (Lecture et écriture) | Specifies the display type for a bar chart with multiple series.
| String |
nullCategoryColor (Lecture et écriture) | The hexadecimal color value for the null category bar. | String |
nullCategoryLabel (Lecture et écriture) | The x-axis label for the null category bar. | String |
rotated (Lecture et écriture) | Specifies whether the chart will be displayed vertically or horizontally.
| Boolean |
showMovingAverage (Lecture et écriture) | Specifies whether the moving average line is displayed for temporal bar charts.
| Boolean |
showNullCategory (Lecture et écriture) | Specifies whether null values are summarized by an additional bar.
| Boolean |
showPreviewChart (Lecture et écriture) | Specifies whether the preview chart will be displayed for grid charts.
| Boolean |
splitCategory (Lecture et écriture) | A second categorical field that adds a separate series or bar for each unique value in the field. | 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 . | String |
timeBinningProperties (Lecture et écriture) | The time binning properties from the TimeBinningProperties class. | Object |
type (Lecture seule) | The string value indicating the chart type. | String |
theme (Lecture et écriture) | Specifies the name of the theme that is applied to the chart. | String |
x (Lecture et écriture) | The field name for the x-axis variable. The field must be a category or a date field. If an empty string is specified, the chart will match the layer symbology. | String |
xAxis (Lecture et écriture) | Sets the properties of the x-axis.
| Object |
y (Lecture et écriture) | The field name or names for the numeric field or fields. This property must specify a single field name or a list of field names. | String |
yAxis (Lecture et écriture) | Sets the properties of the y-axis.
| Object |
Vue d’ensemble des méthodes
Méthode | Explication |
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. |
Méthodes
addToLayer (layer_or_layerfile)
Paramètre | Explication | Type de données |
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)
Paramètre | Explication | Type 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 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()
Exemple de code
Create a bar chart using a feature service and export the chart to an .svg file.
import arcpy
url = r"https://services1.arcgis.com/hLJbHVT9ZrDIzK0I/arcgis/rest/services/CrimesChiTheft/FeatureServer/0"
bar = arcpy.charts.Bar(x="BEAT", aggregation="count", title="Chicago Thefts by Beat", dataSource=url)
bar.exportToSVG('bar.svg', width=800, height=500)
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