Available with Spatial Analyst license.
Available with Image Analyst license.
Summary
Summarizes the values of a raster within the zones of another dataset and reports the results as a table.
Illustration
Usage
A zone is defined as all areas in the input that have the same value. The areas do not have to be contiguous. Both raster and feature can be used for the zone input.
If the Input raster or feature zone data (in_zone_data in Python) is a raster, it must be an integer raster.
If the Input raster or feature zone data (in_zone_data in Python) is a feature, it will be converted to a raster internally using the cell size and cell alignment from the Input value raster (in_value_raster in Python).
When the cell size of the Input raster or feature zone data (in_zone_data in Python) and the Input value raster (in_value_raster in Python) is different, the output cell size will be the Maximum Of Inputs value, and the Input value raster will be used as the snap raster internally. If the cell size is the same but the cells are not aligned, the Input value raster will be used as the snap raster internally. Either of these cases will trigger an internal resampling before the zonal operation is performed.
When the zone and value inputs are both rasters of the same cell size and the cells are aligned, they will be used directly in the tool and will not be resampled internally during tool execution.
If the Input raster or feature zone data (in_zone_data in Python) is a feature, for any of the zone features that do not overlap any cell centers of the value raster, those zones will not be converted to the internal zone raster. As a result, those zones will not be represented in the output. You can manage this by determining an appropriate value for the cell size environment that will preserve the desired level of detail of the feature zones, and specify it in the analysis environment.
If the Input raster or feature zone data (in_zone_data in Python) is a point feature, it is possible to have more than one point contained within any particular cell of the value input raster. For such cells, the zone value is determined by the point with the lowest ObjectID field (for example, OID or FID).
If the Input raster or feature zone data (in_zone_data in Python) has overlapping features, the zonal analysis will be performed for each individual feature.
When specifying the Input raster or feature zone data (in_zone_data in Python), the default zone field will be the first available integer or text field. If no other valid fields exist, the ObjectID field (for example, OID or FID) will be the default.
The Input value raster (in_value_raster in Python) can be either integer or floating point. However, when it is floating-point type, the options for calculating majority, median, minority, and variety will not be available.
For majority and minority calculations, when there is a tie, the output for the zone is based on the lowest of the tied values. See How Zonal Statistics works for more information.
A field or series of fields will be created in the output table, depending on the Statistics type parameter setting. When the value input is integer, all of the statistics (Mean, Majority, Maximum, Median, Minimum, Minority, Percentile, Range, Standard deviation, Sum, and Variety) are available for calculation. If the value input is floating point, the Majority, Minority, Median, Percentile, and Variety statistics will not be calculated.
Supported multidimensional raster dataset types include multidimensional raster layer, mosaic, image service and Esri's CRF.
The data type for each value of the items in the output table is dependent on the zonal calculation being performed. See How Zonal Statistics works for the specific behavior of a statistic.
The number of rows in the output table is the number of zones.
By default, this tool will take advantage of multicore processors. The maximum number of cores that can be used is four.
To use fewer cores, use the parallelProcessingFactor environment setting.
See Analysis environments and Spatial Analyst for additional details on the geoprocessing environments that apply to this tool.
Syntax
ZonalStatisticsAsTable(in_zone_data, zone_field, in_value_raster, out_table, {ignore_nodata}, {statistics_type}, {process_as_multidimensional}, {percentile_values})| Parameter | Explanation | Data Type |
in_zone_data | The dataset that defines the zones. The zones can be defined by an integer raster or a feature layer. | Raster Layer; Feature Layer |
zone_field | The field that contains the values that define each zone. It can be an integer or a string field of the zone dataset. | Field |
in_value_raster | The raster that contains the values on which to calculate a statistic. | Raster Layer |
out_table | The output table that will contain the summary of the values in each zone. The format of the table is determined by the output location and path. By default, the output will be a geodatabase table if in a geodatabase workspace, and a dBASE table if in a file workspace. | Table |
ignore_nodata (Optional) | Specifies whether NoData values in the value input will be ignored in the results of the zone that they fall within.
| Boolean |
statistics_type (Optional) | Specifies the statistic type to be calculated.
| String |
process_as_multidimensional (Optional) | Specifies how the input rasters will be processed if they are multidimensional.
| Boolean |
percentile_values [percentile_values,...] (Optional) | The percentile to calculate. The default is 90, indicating the 90th percentile. The values can range from 0 to 100. The 0th percentile is essentially equivalent to the minimum statistic, and the 100th percentile is equivalent to maximum. A value of 50 will produce essentially the same result as the median statistic. This option is only supported if the statistics_type parameter is set to PERCENTILE or ALL. | Double |
Code sample
This example summarizes the values of a raster within the zones defined by a polygon shapefile and records the results in a table.
import arcpy
from arcpy import env
from arcpy.ia import *
env.workspace = "C:/sapyexamples/data"
outZSaT = ZonalStatisticsAsTable("zones.shp", "Classes", "valueforzone",
"zonalstattblout", "NODATA", "SUM")This example summarizes the values of a raster within the zones defined by a polygon shapefile and records the results in a table.
# Name: ZonalStatisticsAsTable_Ex_standalone.py
# Description: Summarizes values of a multidimensional raster within the zones
# of another dataset and reports the results to a table.
# Requirements: Image Analyst Extension
# Import system modules
import arcpy
from arcpy.ia import *
# Check out the ArcGIS Image Analyst extension license
arcpy.CheckOutExtension("ImageAnalyst")
# Set the analysis environments
arcpy.env.workspace = "C:/sapyexamples/data"
# Set the local variables
inZoneData = "zones.shp"
zoneField = "sampleID"
inValueRaster = "multidimensional_valueraster.crf"
outTable = "zonalstattblout02.dbf"
# Execute ZonalStatisticsAsTable
outZSaT = ZonalStatisticsAsTable(inZoneData, zoneField, inValueRaster,
outTable, "NODATA", "MAXIMUM", "ALL_SLICES")Environments
Licensing information
- Basic: Requires Image Analyst or Spatial Analyst
- Standard: Requires Image Analyst or Spatial Analyst
- Advanced: Requires Image Analyst or Spatial Analyst