Global functions

Available with Spatial Analyst license.

Overview

ArcGIS AllSource has a category of raster function called global functions. Global functions allow you to perform processing at a specific resolution and extent. By default, global functions process rasters at the source resolution and full extent. This means that applying a global function may take some time, depending on the size of the outputs. You need to exercise prudence when using global functions, as applying them on inputs that are large, such as mosaic datasets, may result in long processing times.

Global functions are distinguishable from regular raster functions in many ways. All global functions have a hammer icon to distinguish them from other raster functions. When you open a global function, or a raster function template that contains a global function, a notification appears at the top of the function page indicating that these functions may take some time to complete. When editing the parameters of a global function in the Raster Function Editor or using a global function in a raster function template, the global function node has an icon on it that distinguishes it from regular raster functions.

It is recommended that when using global functions, you process data using the distributed raster analysis tools. This allows you to process data in a distributed fashion and allows processing time by global functions to be minimized.

List of global raster functions

Global raster functions

Function name	Description
Boundary Clean function	Smooths the boundary between zones. This function is in the Data Management category.
Corridor function	Calculates the sum of accumulative costs for two input accumulative cost rasters. This function is in the Distance (Legacy) category.
Cost Allocation function	Calculates, for each cell, its least-cost source based on the least accumulative cost over a cost surface. This function is in the Distance (Legacy) category.
Cost Back Link function	Defines the neighbor that is the next cell on the least-accumulative cost path to the least-cost source. This function is in the Distance (Legacy) category.
Cost Distance function	Calculates the least-accumulative cost distance for each cell from or to the least-cost source over a cost surface. This function is in the Distance (Legacy) category.
Cost Path function	Calculates the least-cost path from a source to a destination. This function is in the Distance (Legacy) category.
Distance Accumulation function	Calculates accumulated distance for each cell to sources, allowing for straight-line distance, cost distance, and true surface distance, as well as vertical and horizontal cost factors. This function is in the Distance category.
Distance Allocation function	Calculates distance allocation for each cell to the provided sources based on straight-line distance, cost distance, and true surface distance, as well as vertical and horizontal cost factors. This function is in the Distance category.
Euclidean Allocation function	Calculates, for each cell, the nearest source based on Euclidean distance. This function is in the Distance (Legacy) category.
Euclidean Back Direction function	Calculates, for each cell, the direction, in degrees, to the neighboring cell along the shortest path back to the closest source while avoiding barriers. This function is in the Distance (Legacy) category.
Euclidean Direction function	Calculates, for each cell, the direction, in degrees, to the nearest source. This function is in the Distance (Legacy) category.
Euclidean Distance function	Calculates, for each cell, the Euclidean distance to the closest source. This function is in the Distance (Legacy) category.
Expand function	Expands specified zones of a raster by zones by a specified number of cells. This function is in the Data Management category.
Fill function	Fills sinks and peaks in an elevation surface raster to remove small imperfections in the data. This function is in the Hydrology category.
Flow Accumulation function	Creates a raster layer of accumulated flow into each cell. A weight factor can optionally be applied. This function is in the Hydrology category.
Flow Direction function	Creates a raster layer of flow direction from each cell to its steepest downslope neighbor. This function is in the Hydrology category.
Flow Distance function	Computes the minimum downslope horizontal or vertical distance to cell(s) on a stream or river into which they flow. This function is in the Hydrology category.
Flow Length function	Creates a raster layer of upstream or downstream distance, or weighted distance, along the flow path for each cell. This function is in the Hydrology category.
Kernel Density function	Calculates a magnitude-per-unit area from point or polyline features, using a kernel function to fit a smoothly tapered surface to each point or polyline. This function is in the Analysis category.
Least Cost Corridor function	Calculates the sum of two accumulative cost distance rasters with the option to apply a threshold based on percentage or accumulative cost. This function is in the Distance category.
Least Cost Path function	Calculates the least-cost path from a source to a destination. The least accumulative cost distance is calculated for each cell over a cost surface to the nearest source. This produces an output raster that records the least-cost path, or paths, from selected locations to the closest source cells defined within the accumulative cost surface, in terms of cost distance. This function is in the Distance (Legacy) category.
Nibble function	Replaces selected cells of a raster with the value of their nearest neighbor. This is useful for editing areas of a raster in which the data may be erroneous. This function is in the Data Management category.
Optimal Path As Raster function	Calculates the optimal path from destinations to sources. This function is in the Distance category.
Path Distance function	Calculates, for each cell, the least accumulative cost distance from or to the least-cost source, while accounting for surface distance along with horizontal and vertical cost factors. This function is in the Distance (Legacy) category.
Path Distance Allocation function	Calculates the least-cost source for each cell based on the least accumulative cost over a cost surface, while accounting for surface distance along with horizontal and vertical cost factors. This function is in the Distance (Legacy) category.
Path Distance Back Link function	Defines the neighbor that is the next cell on the least accumulative cost path to the least-cost source, while accounting for surface distance along with horizontal and vertical cost factors. This function is in the Distance (Legacy) category.
Region Group function	Records, for each cell in the output, the identity of the connected region to which that cell belongs. A unique number is assigned to each region. This function is in the Data Management category.
Shrink function	Shrinks specified zones of a raster by a specified number of cells. This function is in the Data Management category.
Sink function	Creates a raster layer identifying all sinks or areas of internal drainage. This function is in the Hydrology category.
Snap Pour Point function	Snaps pour points to the cell of highest flow accumulation within a specified distance. This function is in the Hydrology category.
Stream Link function	Assigns unique values to sections of a raster linear network between intersections. This function is in the Hydrology category.
Stream Order function	Creates a raster layer that assigns a numeric order to segments of a raster representing branches of a linear network. This function is in the Hydrology category.
Viewshed function	Determines the raster surface locations visible to a set of observer features using geodesic methods. This function is in the Surface category.
Watershed function	Determines the contributing area above a set of cells in a raster. This function is in the Hydrology category.
Zonal Statistics function	Calculates statistics on values of a raster within the zones of another dataset. This function is in the Statistical category. License: Available with an Image Analyst or Spatial Analyst extension license.

Geoprocessing environment settings

Geoprocessing environment settings for global functions are controlled at the application level. Setting processing environments in ArcGIS AllSource can be done by clicking the Environments button on the Analysis tab. See Analysis environments and Spatial Analyst for additional details on environment settings.