Frequency (Analysis)
Summary
Reads a table and a set of fields and creates a new table containing unique field values and the number of occurrences of each unique field value.
Usage
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The output table will contain the field Frequency and the specified frequency field(s) and summary field(s).
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The output table will contain the frequency calculation for each attribute value combination of the specified frequency field(s).
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If a summary field is specified, the unique attribute values of the frequency calculation are summarized by the numeric attribute values of each summary field.
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When using layers, only the currently selected features are used in calculations.
Syntax
Parameter | Explanation | Data Type |
in_table |
The table containing the field(s) that will be used to calculate frequency statistics. This table can be an INFO or OLE DB table, a dBASE or a VPF table, or a feature class table. | Table View; Raster Layer |
out_table |
The table that will store the calculated frequency statistics. | Table |
frequency_fields [frequency_fields,...] |
The attribute field or fields that will be used to calculate frequency statistics. | Field |
summary_fields [summary_fields,...] (Optional) |
The attribute field or fields to sum and add to the output table. Null values are excluded from this calculation. | Field |
Code Sample
The following Python window script demonstrates how to use the Frequency function in immediate mode.
import arcpy
arcpy.env.workspace = "C:/data/Portland.gdb/Taxlots"
arcpy.Frequency_analysis("taxlots",
"C:/output/output.gdb/tax_frequency",
["YEARBUILT", "COUNTY"],
["LANDVAL", "BLDGVAL", "TOTALVAL"])
The following stand-alone script demonstrates how to use the Frequency function.
# Name: Frequency_Example2.py
# Description: Run Frequency on a table
# Import system modules
import arcpy
# Set environment settings
arcpy.env.workspace = "C:/data/Portland.gdb/Taxlots"
# Set local variables
inTable = "taxlots"
outTable = "C:/output/output.gdb/tax_frequency"
frequencyFields = ["YEARBUILT", "COUNTY"]
summaryFields = ["LANDVAL", "BLDGVAL", "TOTALVAL"]
# Execute Frequency
arcpy.Frequency_analysis(inTable, outTable, frequencyFields, summaryFields)
The following stand-alone script demonstrates how to use many geoprocessing scripting functions, including the Frequency function.
# Name: Frequency_Example3.py
# Description: Break all multipart features into singlepart features,
# and generate a report of which features were separated.
# Import system modules
import arcpy
# Create variables for the input and output feature classes
inFeatureClass = "c:/data/gdb.gdb/vegetation"
outFeatureClass = "c:/data/gdb.gdb/vegetation_singlepart"
try:
# Create list of all fields in inFeatureClass
fieldNameList = [field.name for field in arcpy.ListFields(inFeatureClass)]
# Add a field to the input this will be used as a unique identifier
arcpy.AddField_management(inFeatureClass, "tmpUID", "double")
# Determine what the name of the Object ID is
OIDFieldName = arcpy.Describe(inFeatureClass).OIDFieldName
# Calculate the tmpUID to the OID
arcpy.CalculateField_management(inFeatureClass, "tmpUID",
"[" + OIDFieldName + "]")
# Run the tool to create a new fc with only singlepart features
arcpy.MultipartToSinglepart_management(inFeatureClass, outFeatureClass)
# Check if there is a different number of features in the output
# than there was in the input
inCount = int(arcpy.GetCount_management(inFeatureClass).getOutput(0))
outCount = int(arcpy.GetCount_management(outFeatureClass).getOutput(0))
if inCount != outCount:
# If there is a difference, print out the FID of the input
# features which were multipart
arcpy.Frequency_analysis(outFeatureClass,
outFeatureClass + "_freq", "tmpUID")
# Use a search cursor to go through the table, and print the tmpUID
print("Multipart features from {0}".format(inFeatureClass))
for row in arcpy.da.SearchCursor(outFeatureClass + "_freq",
["tmpUID"], "FREQUENCY > 1"):
print int(row[0])
else:
print("No multipart features were found")
except arcpy.ExecuteError:
print(arcpy.GetMessages())
except Exception as e:
print(e)