Foreach

Disponible avec une licence Image Analyst.

Disponible avec une licence Spatial Analyst.

Synthèse

Creates a raster object by applying a raster function or a customized function template to every slice in the input multidimensional raster.

Discussion

Use the Foreach function to apply a raster function to every slice in a multidimensional raster dataset. To apply a raster function to a single slice, use the Subset function before using Foreach.

This function creates a raster object that contains the variables and dimensions of the input multidimensional raster, processed using a raster function. The referenced raster dataset for the raster object is temporary. To make it permanent, you can call the raster object's save method.

Syntaxe

Foreach (in_raster, raster_function, {raster_function_arguments})

Paramètre	Explication	Type de données
in_raster	The input multidimensional raster dataset.	Raster
raster_function	The name of a raster function or the path to a custom raster function (.rft.xml file) to apply to every slice in the input multidimensional raster.	String
raster_function_arguments	The parameters and values associated with the raster function or function chain. If not specified, default values will be used. For example, the Tasseled Cap raster function does not require any arguments; the input is a single raster, so there is no need to specify arguments. The Arithmetic raster function, however, requires 5 input parameters: Raster, Raster2, Operation, Cellsize Type and Extent Type. To use Arithmetic with the Apply function, Raster and Raster2 are defined in the in_raster parameter, and the remaining parameters have default values, so if nothing is specified for those parameters, the default values will be used. For information about the function arguments for each raster function, see Raster function objects.	Dictionary

Valeur renvoyée

Type de données	Explication
Raster	The output multidimensional raster.

Exemple de code

Foreach example

Calculate NDVI for each slice in a time series of Landsat 7 scenes.

import arcpy
from arcpy.ia import *

arcpy.CheckOutExtension("ImageAnalyst")

# Create multidimensional raster object from 
# Landsat7 time series data in a mosaic dataset
in_raster = Raster('C:\\test.gdb\\Landsat7', True) 

# Calculate NDVI for each scene in the time series
out_NDVI_raster = Foreach(
	in_raster, "NDVI", {'VisibleBandID':3,'InfraredBandID':4})