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Extract Values to Points
Release 9.2 Last modified January 3, 2008

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Extracts the cell values of a raster based on a set of points.

Usage tips

Command line and Scripting

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.
When Extract Values to Point is used on a multiband raster, it will only operate on the first band.
The Extract Values to Points tool can be used with a floating-point input raster. In this case, the resulting output point dataset will only contain attributes from the input feature data and the value of the cell, as determined by the interpolation option.
The output shapefile will have at least the RASTERVALU field added. All other items will be appended after the RASTERVALU field.
If the output point feature dataset is a shapefile, there can be no fields in the input raster with a name more than 10 characters in length. If there are, these fields must be renamed before using the Extract Values to Points tool.
For the RASTERVALU field of the attribute table, NoData cells in the value raster will be given a value of -9999.
The following environment settings affect this tool:
- General: Current Workspace, Scratch Workspace, Output Coordinate system, Output Extent, Qualified Field Names, XY Resolution, XY Tolerance, Z Resolution, Z Tolerance.
- Geodatabase: Output CONFIG keyword, Output Spatial Grid 1, 2, 3, Output XY domain, Output M domain, Output Z domain.
- Raster Analysis: Cell size.

Map Algebra

ExtractValuesToPoints is only available from the Raster Calculator. It has not been implemented for Workstation GRID.
Only point shapefiles are supported as the <points> dataset.
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 sample cell. The interpolation option will use bilinear interpolation to interpolate a value for the cell center.
ExtractValuesToPoints can be used with a floating-point input raster. In this case, the resulting output point dataset will only contain attributes from the input point shapefile and the value of the cell, as determined by the interpolation option.
The output shapefile will have at least the RASTERVALU field added. All other items will be appended after the RASTERVALU field.
For the RASTERVALU field of the attribute table, NoData cells in the value raster will be given a value of -9999.
There can be no fields in the value raster with a name more than 10 characters in length. If there are, these fields must be renamed before using ExtractValuesToPoints.
Learn more about how to specify the input raster dataset in the Map Algebra expression of Raster Calculator.

ArcObjects

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 sample cell. The interpolation option will use bilinear interpolation to interpolate a value for the cell center.
When Extract Values to Point is used on a multiband raster layer, it will only operate on the first band.
ExtractValuesToPoints can be used with a floating-point input raster. In this case, the resulting output point dataset will only contain attributes from the input feature data and the value of the cell, as determined by the interpolation option.
The output shapefile will have at least the RASTERVALU field added. All other items will be appended after the RASTERVALU field.
There can be no fields in valueRaster with a name more than 10 characters in length. If there are, these fields must be renamed before using ExtractValuesToPoints.
For the RASTERVALU field of the attribute table, NoData cells in the value raster will be given a value of -9999.

Command line syntax
An overview of the Command Line window
ExtractValuesToPoints_sa <in_point_features> <in_raster> <out_point_features> {NONE | INTERPOLATE} {VALUE_ONLY | ALL}

Parameter	Explanation	Data Type
<in_point_features>	The name of a point shapefile to which you want to add raster values.	Composite Geodataset
<in_raster>	The name of a raster dataset to whose values you want to add a point dataset.	Composite Geodataset
<out_point_features>	The output point feature dataset recording the sample raster values.	Feature Class
{NONE \| INTERPOLATE}	Specifies whether or not interpolation will be used. NONE — No interpolation will be applied; the value of the cell center will be used. 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
{VALUE_ONLY \| ALL}	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

Data types for geoprocessing tool parameters

Command line example

ExtractValuesToPoints_sa C:/data/points1.shp C:/data/raster1 C:/data/out_points.shp NONE VALUE_ONLY

Scripting syntax
About getting started with writing geoprocessing scripts
ExtractValuesToPoints_sa (in_point_features, in_raster, out_point_features, interpolate_values, add_attributes)

Parameter	Explanation	Data Type
in_point_features (Required)	The name of a point shapefile to which you want to add raster values.	Composite Geodataset
in_raster (Required)	The name of a raster dataset to whose values you want to add a point dataset.	Composite Geodataset
out_point_features (Required)	The output point feature dataset recording the sample 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. 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

Data types for geoprocessing tool parameters

Script example

# ExtractValuesToPoints_sample.py
# Description: 
#   Extracts the cells of a raster based on a set of points.
# Requirements: None
# Author: ESRI
# Date: Sept 6, 2005
# Import system modules
import arcgisscripting

# Create the Geoprocessor object
gp = arcgisscripting.create()

try:
    # Set local variables 
    InPointsFC = "C:/data/points1.shp"
    InRaster = "C:/data/raster1"
    OutPointsFC = "C:/data/out_points.shp"

    # Check out Spatial Analyst extension license
    gp.CheckOutExtension("Spatial")

    # Process: ExtractValuesToPoints
    gp.ExtractValuesToPoints_sa(InPointsFC, InRaster, OutPointsFC, "NONE", "VALUE_ONLY")

except:
    # If an error occurred while running a tool, then print the messages.
    print gp.GetMessages()

Map Algebra syntax
ExtractValuesToPoints (<point_vector>, <value_grid>, {NONE | INTERPOLATE}, {VALUE_ONLY | ALL} )

Parameter	Explanation
<point_vector>	The name of a point shapefile to which you want to add raster values.
<value_grid>	The name of a raster dataset whose values you want to add to a point dataset.
{NONE \| INTERPOLATE}	Determines how the value of the cell is obtained. NONE — 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.
{VALUE_ONLY \| ALL}	Determines if 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.

Map Algebra example

ExtractValuesToPoints (points1.shp, surface1)	
ExtractValuesToPoints (capitals.shp, elev2, INTERPOLATE, ALL)

ArcObjects syntax
IExtractionOp::ExtractValuesToPoints (pointDataset As IGeoDataset, valueRaster As IGeoDataset, [interpolateValues As Boolean], [allAttributes As Boolean]) As IGeoDataset

Parameter	Explanation
pointDataset	A feature class descriptor defining the input point feature dataset to which you want to add raster values.
valueRaster	An input raster dataset whose values you want to add to a point dataset.
interpolateValues	A Boolean value that determines how the value of the cell is obtained. False — The value of the cell center will be used. This is the default. True — 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.
allAttributes	A Boolean value that determines if raster attributes are written to the output point feature dataset. False — Only the value of the input raster is added to the point attributes. This is the default. True — All the fields from the input raster (except Count) will be added to the point attributes.

ArcObjects example


' Function ExtractValuesToPoints(pointDataset As IGeoDataset, valueRaster As IGeoDataset, 
'   [interpolateValues 'As Boolean = False], [allAttributes As Boolean = False]) As IGeoDataset

Dim pExtractionOp As IExtractionOp2
Set pExtractionOp = New RasterExtractionOp

' Get raster dataset
Dim pRas01 As IRaster
Set pRas01 = readRasterFromDisk("c:\data\myRaster1")

Dim pFC01 As IFeatureClass
Set pFC01 = readPointFeatureFromDisk("c:\data\myPts.shp")

' Call extraction method
Dim pOutGeoDS As IGeoDataset
Set pOutGeoDS = pExtractionOp.ExtractValuesToPoints(pFC01, pRas01, True)

Extract Values to Points

Command line example

Script example

Map Algebra example

ArcObjects example