Extract Values to Points

Available with Spatial Analyst license.

Summary

Extracts the cell values of a raster based on a set of point features and records the values in the attribute table of an output feature class.

Usage

• All fields from the input point feature class will be carried over to the output point feature class.

• The output feature class will have a new field added to it named RASTERVALU.

  Note:

  This field cannot already exist in the attribute table of the input features. If it does, an error will occur. If you wish to keep the original information, before performing Extract Values to Points you can add a new field (for example, RASVAL1) to the attribute table, calculate the values to it, and then delete the original RASTERVALU field.

• To add attributes from the input raster table, check the Append all the input raster attributes to the output point features option (ALL for the add_attributes parameter in Python). The attributes will be carried over as-is to the output point features, keeping the same values. Depending on the nature of the property being recorded, some of the attribute values may need to be recalculated.

• The shapefile format has limitation on the maximum length of a field name of 10 characters. As a result, any fields that are appended to the attribute table of an output shapefile will have their names truncated and made unique by default. This may make it difficult to distinguish between the fields, particularly if the names are long or very similar. In this case, it is suggested to output to a file geodatabase instead.

• When a multiband raster is specified as the Input Raster (in_raster in Python), only the first band will be used.

  To process a different band, specify the band to use.

  To extract values from multiple rasters or a multiband raster dataset, use the Extract Multi Values To Points tool.

• Locations that sample NoData cells in the input raster will be given a <null> value in an output geodatabase table. For output to shapefiles, since the concept of null is not supported, a value of -9999 will be given.

• The interpolation option determines how the values will be obtained from the raster. The default option is to use the value at the center of the cell being sampled. The interpolation option will use bilinear interpolation to interpolate a value for the cell center.

• Multipoint datasets are not supported as input.

• See Analysis environments and Spatial Analyst for additional details on the geoprocessing environments that apply to this tool.

Syntax

ExtractValuesToPoints (in_point_features, in_raster, out_point_features, {interpolate_values}, {add_attributes})

Parameter	Explanation	Data Type
in_point_features	The input point features defining the locations from which you want to extract the raster cell values.	Feature Layer
in_raster	The raster dataset whose values will be extracted. It can be an integer or floating-point type raster.	Raster Layer
out_point_features	The output point feature dataset containing the extracted raster values.	Feature Class
interpolate_values (Optional)	Specifies whether or not interpolation will be used. NONE — No interpolation will be applied; the value of the cell center will be used. This is the default. INTERPOLATE — The value of the cell will be calculated from the adjacent cells with valid values using bilinear interpolation. NoData values will be ignored in the interpolation unless all adjacent cells are NoData.	Boolean
add_attributes (Optional)	Determines if the raster attributes are written to the output point feature dataset. VALUE_ONLY — Only the value of the input raster is added to the point attributes. This is the default. ALL — All the fields from the input raster (except Count) will be added to the point attributes.	Boolean

Code sample

ExtractValuesToPoints example 1 (Python window)

This example extracts the cell values from a raster based on locations defined by a point shapefile, and creates an output point feature class of those values.

import arcpy
from arcpy import env
from arcpy.sa import *
env.workspace = "C:/sapyexamples/data"
ExtractValuesToPoints("rec_sites.shp", "elevation",
                      "C:/sapyexamples/output/outValPnts","INTERPOLATE",
                      "VALUE_ONLY")

ExtractValuesToPoints example 2 (stand-alone script)

This example extracts the cell values from a raster based on locations defined by a point shapefile, and creates an output point shapefile of those values.

# Name: ExtractValuesToPoints_Ex_02.py
# Description: Extracts the cells of a raster based on a set of points.
# Requirements: Spatial Analyst Extension

# Import system modules
import arcpy
from arcpy import env
from arcpy.sa import *

# Set environment settings
env.workspace = "C:/sapyexamples/data"

# Set local variables
inPointFeatures = "rec_sites.shp"
inRaster = "elevation"
outPointFeatures = "C:/sapyexamples/output/extractvaluespts.shp"

# Check out the ArcGIS Spatial Analyst extension license
arcpy.CheckOutExtension("Spatial")

# Execute ExtractValuesToPoints
ExtractValuesToPoints(inPointFeatures, inRaster, outPointFeatures,
                      "INTERPOLATE", "VALUE_ONLY")

Environments

• Auto Commit
• Current Workspace
• Default Output Z Value
• Extent
• Geographic Transformations
• Mask
• M Resolution
• M Tolerance
• Maintain Spatial Index
• Output CONFIG Keyword
• Output Coordinate System
• Output has M values
• Output has Z values
• Output M Domain
• Output XY Domain
• Output Z Domain
• Qualified Field Names
• Scratch Workspace
• Snap Raster
• Transfer Field Domain Descriptions
• XY Resolution
• XY Tolerance
• Z Resolution
• Z Tolerance

Licensing information

• ArcGIS Desktop Basic: Requires Spatial Analyst
• ArcGIS Desktop Standard: Requires Spatial Analyst
• ArcGIS Desktop Advanced: Requires Spatial Analyst