A raster function template contains a chain of functions and inputs as values or variables. The function template can then be added to a mosaic dataset, a mosaic dataset item, or a function raster layer to process pixels on-the-fly.
A function template contains raster functions as well as properties of the template:
- Name—The template name.
- Description—The description of the template.
- Help—The help content that you want users to see when using this template.
- Type—Indicates the template applied to a mosaic dataset, mosaic dataset items, or item groups specified in the Definition Query.
- Group Field Name—The field name in the mosaic dataset that defines a group. This only appears when you select Item Group as the Type.
- Tag Field Name—The field name in the mosaic dataset that contains the variable names used in raster functions. This only appears when you select Item Group as the Type.
- Thumbnail—A snapshot of the mosaic dataset can be added to the template as an image.
When you select Item Group as the Type, you can use the Group Field Name and Tag Field Name properties to group items so that multiple items from a mosaic dataset can be passed to a raster function or raster function chain. This workflow is typically used for multidimensional mosaic datasets where rasters with the same dimension values are considered one group, and tag names are usually used as the variables used in the computation. For more information, see Using Mosaic Dataset Items in Raster Function Templates.
The Multidimensional Rules properties are available for all local raster functions with two or more input rasters. The properties control the processing rules for multidimensional raster computing when there are two or more multidimensional raster datasets being processed by the raster function.
- Match Variables—When this property is checked, the raster function will only proceed if the variables in the two or more input multidimensional rasters have the same name. If none of the variable names match, you will see an error message stating that no variables have matching names. This is the default. When it's not checked, the input multidimensional rasters can have variables with different names. This is necessary for functions such as the Heat Index function, which requires a relative humidity input and a temperature input.
- Union Dimensions—When this property is not checked, the raster function will only proceed if the dimensions in the two or more input multidimensional rasters have the same name. If none of the dimension names match, you will see an error message stating that no variables have matching names. This is the default. When checked, the dimensions do not have to have matching names, and the result will be the union of the dimensions. For example, if you add two multidimensional rasters that both have an ocean temperature variable named "temp", but one measures along dimension Time and one measures along dimension Depth, the result will be a multidimensional raster with both Time and Depth dimensions where the temperature variable has been added together for each combination of dimensions.