If a reserved field (for example, OBJECTID, FID, or OID) is selected for the Zone field, then this may cause some ambiguity in the result. If no other valid fields exist, the ObjectID field (for example, OID or FID) will be the default. When specifying the input zone data, the default zone field will be the first available valid field. This will help ensure you consistently get the expected results. It is recommended to only use rasters as the zone input, as it offers you greater control over the vector-to-raster conversion. Since the feature input is converted to a raster, each location can only have one value.Īn alternative method is to process the zonal statistics iteratively for each of the polygon zones and collate the results.
![zonal statistics arcgis zonal statistics arcgis](https://i.ytimg.com/vi/S3Bj_SWMvBo/maxresdefault.jpg)
If the zone feature input has overlapping polygons, the zonal analysis will not be performed for each individual polygon.
![zonal statistics arcgis zonal statistics arcgis](https://desktop.arcgis.com/en/arcmap/10.3/tools/spatial-analyst-toolbox/GUID-9F387858-9D6B-4606-BF30-13A76A58945F-web.gif)
For such cells, the zone value is determined by the point with the highest feature ID. If the zone input is a point feature dataset, it is possible to have more than one point contained within any particular cell of the value input raster. If you have fewer results in the output than you expected, you need to determine an appropriate raster resolution that will represent the detail of your feature input, and use this resolution as the Cell Size of the Raster Analysis Settings of the Environment. The result from this conversion will give an indication about what the default output of the zonal operation will be. To demonstrate this, try converting the feature dataset to a raster with the appropriate feature-to-raster conversion tool and specify the resolution to be that of the Value raster. If the areas of single features are similar to or smaller than the area of single cells in the value raster, in the feature-to-raster conversion some of these zones may not be represented. If the zone input is a feature dataset with relatively small features, keep in mind that the resolution of the information needs to be appropriate relative to the resolution of the value raster. Generate an attribute table for it as described in the previous tip and use the resulting raster as your Zone input. If this happens, convert your feature dataset directly with Feature To Raster, Polygon To Raster, Point To Raster, or Polyline To Raster. Since the internal raster must have an attribute table, an error will occur if one was not created in the conversion. To ensure that the results of the conversion will align properly with the value raster, it is recommended that you check to ensure the extent and snap raster are set appropriately in the environment settings and the raster settings. If the zone input is a feature dataset, a vector-to-raster conversion will be internally applied to it. You can use Build Raster Attribute Table to create one. The attribute table is usually created automatically for integer rasters, but may not be under certain circumstances. If the zone input is a raster dataset, it must have an attribute table. To avoid this situation, either Resample the coarser input rasters to the resolution of the finer input raster, or set the Cell size to Minimum Of Inputs in the Raster Analysis environment. Should there be any NoData cells in the inputs, the resampling may cause there to be larger areas of NoData in your output than you might have expected. If the resolutions are different, an internal resampling is applied to make them match before the zonal operation is performed. When the zone and value inputs are both rasters of the same resolution, they will be used directly. Both raster and feature datasets can be used for the zone input.
![zonal statistics arcgis zonal statistics arcgis](https://i.ytimg.com/vi/X3NuuREUTvQ/maxresdefault.jpg)
Learn more about how Zonal Statistics works Illustration ZonalStatisticsAsTable(ZoneRas, "Value", ValRas, OutTable, "ALL") UsageĪ zone is defined as all areas in the input that have the same value. Summarizes the values of a raster within the zones of another dataset and reports the results to a table.