Symbolize by Dot Density (Business Analyst)
Zusammenfassung
Thematically maps a feature class based on a numeric field as dots on the map to convey the intensity of an attribute.
Verwendung
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This is a type of thematic map in which a certain number of dots are used to represent a numeric attribute associated with a polygon layer.
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When selecting the dot size, keep a perspective on the data you are symbolizing. For example, selecting a dot size of 10 based on 2004 total population per county would result in a map that would be mostly black, since the dot distribution would be too dense to visualize. A better choice would be to select a dot size of 100 or 1,000 to better see the distribution of population.
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The dots are evenly distributed across each polygon in your feature class.
Syntax
Parameter | Erläuterung | Datentyp |
InputFeatureLayer |
The input feature layer. | Feature Layer |
Field |
The attribute field used to define the thematic map. | String |
DotSizeParameterName |
The numeric value that represents the field selection to be symbolized. | Double |
ColorParameterName |
The color assigned to the points to be symbolized. | Long |
UseSelectedFeatures (optional) |
Identifies the features that will be used to generate the thematic map.
| Boolean |
Codebeispiel
# Name: SymbolizeByDotDensity.py # Description: Symbolizes block groups by dot density using total population. # Author: ESRI # Import system modules import arcpy arcpy.ImportToolbox("C:\Program Files\ArcGIS\Desktop10.0\ArcToolbox\Toolboxes\Business Analyst Tools.tbx") try: # Acquire extension license arcpy.CheckOutExtension("Business") # Defines the parameters for the Symbolize by Dot Density tool Input = "C:/Program Files/ArcGIS/Desktop10.0/Business Analyst/Data/BDS/esri_bg.bds" Fld= "TOTPOP_CY" # Thematically symbolizes a polygon layer by dot density # Red point is –65536 arcpy.SymbolizeByDotDensity_ba(sInput, sFld, 10, –65536) # Release extension license arcpy.CheckInExtension("Business") except: print arcpy.GetMessages(2)