Understanding the following list of terms is essential for gaining a complete knowledge of the Raster Cell Iterator. The definitions below will help you when reading the other topics in this area.
Raster Cell Iterator
A Python class to iterate through cells of a single-band or multiband raster dataset.
A Raster object references a raster. A raster object is either created by casting a raster dataset, or is returned when executing a geoprocessing tool that returns an output raster dataset. The raster object has properties and methods that can be used for further analysis.
A RasterInfo object references a raster's metadata properties. A rasterInfo object can be used to create an empty raster. Each Raster object has a rasterInfo object tied to it, and it can be accessed using the getRasterInfo() method of the raster object.
When an iterator is implicitly defined on a raster object.
When an iterator is explicitly defined using the RasterCellIterator() object.
Raster analysis environment
The raster analysis environment defines the extent, cell size, and coordinate system in which the Raster Cell Iterator will perform analysis. It defines the geographic area where the iteration occurs on the raster data. For more information, see How the analysis window is determined in Spatial Analyst.
Padding does not change the output in any way, but it improves performance if you are accessing neighborhood cell values while iterating through cell locations.
In computing, NaN means not a number. When NoData is read from a raster using index notation, NaN is returned in Python. When NaN is assigned to a raster cell, it is interpreted as a NoData cell.
Indexing a raster object allows access to specific cells within single-band and multiband raster datasets by the use of square brackets that contain a list of indexes.
A way to reference neighborhood cells within an iteration, relative to the position of the cell being iterated on.
For example, if the cell being iterated upon has indexes [i, j], its immediate neighboring cells can be referenced using relative indexes such as [i-1, j-1], [i, j-1], [i+1, j-1], and so on.
A sparse raster is one in which a substantial number of NoData cells are present.
State of a raster
The state of a raster is that which is defined by its cell values at each iteration. If any cells and their neighboring cells are modified over the course of an iteration, then the state of the raster has changed.