Kernel Interpolation With Barriers (Geostatisical Analyst)

Summary

A moving window predictor that uses the shortest distance between points so that points on either side of the line barriers are connected.

Usage

Syntax

KernelInterpolationWithBarriers_ga (in_features, z_field, out_ga_layer, {out_raster}, {cell_size}, {in_barrier_features}, {kernel_function}, {bandwidth}, {power}, {ridge}, {output_type})
ParameterExplanationData Type
in_features

The input point features containing the z-values to be interpolated.

Feature Layer
z_field

Field that holds a height or magnitude value for each point. This can be a numeric field or the Shape field if the input features contain z-values or m-values.

Field
out_ga_layer

The geostatistical layer produced. This layer is required output only if no output raster is requested.

Geostatistical Layer
out_raster
(Optional)

The output raster. This raster is required output only if no output geostatistical layer is requested.

Raster Dataset
cell_size
(Optional)

The cell size at which the output raster will be created.

This value can be explicitly set under Raster Analysis from the Environment Settings. If not set, it is the shorter of the width or the height of the extent of the input point features, in the input spatial reference, divided by 250.

Analysis Cell Size
in_barrier_features
(Optional)

Absolute barrier features using non-Euclidean distances rather than line-of-sight distances.

Feature Layer
kernel_function
(Optional)

The kernel function used in the simulation.

  • QUARTIC Fourth-order polynomial function.
  • EXPONENTIAL The function grows or decays proportionally.
  • GAUSSIAN Bell-shaped function that falls off quickly towards plus/minus infinity.
  • EPANECHNIKOV A discontinuous parabolic function.
  • POLYNOMIAL5 Fifth-order polynomial function.
  • CONSTANTAn indicator function.
Kernel functions
String
bandwidth
(Optional)

Used to specify the maximum distance at which data points are used for prediction. With increasing bandwidth, prediction bias increases and prediction variance decreases.

Double
power
(Optional)

Sets the order of the polynomial.

Long
ridge
(Optional)

Used for the numerical stabilization of the solution of the system of linear equations. It does not influence predictions in the case of regularly distributed data without barriers. Predictions for areas in which the data is located near the feature barrier or isolated by the barriers can be unstable and tend to require relatively large ridge parameter values.

Double
output_type
(Optional)

Surface type to store the interpolation results.

  • PREDICTIONPredicition surfaces are produced from the interpolated values.
  • PREDICTION_STANDARD_ERROR Standard Error surfaces are produced from the standard errors of the interpolated values.
String

Code Sample

KernelInterpolationWithBarriers (Python window)

Interpolate point features onto a rectangular raster using a barrier feature class.

import arcpy
arcpy.env.workspace = "C:/gapysamples/data"
arcpy.KernelInterpolationWithBarriers_ga("ca_ozone_pts", "OZONE", "outKIWB",
                                         "C:/gapyexamples/output/kiwbout", "2000",
                                         "ca_outline", "QUARTIC", "", "", "50", "PREDICTION")
KernelInterpolationWithBarriers (stand-alone script)

Interpolate point features onto a rectangular raster using a barrier feature class.

# Name: KernelInterpolationWithBarriers_Example_02.py
# Description: Kernel Interpolation with Barriers is a moving window predictor
#   that uses non-Euclidean distances.
# Requirements: Geostatistical Analyst Extension

# Import system modules
import arcpy

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

# Set local variables
inPointFeatures = "ca_ozone_pts.shp"
zField = "ozone"
outLayer = "outKIWB"
outRaster = "C:/gapyexamples/output/kiwbout"
cellSize = 2000.0
inBarrier = "ca_outline.shp"
kernelFunction = "QUARTIC"
bandwidth = ""
power = ""
ridgeParam = "50"
outputType = "PREDICTION"

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

# Execute KernelInterpolationWithBarriers
arcpy.KernelInterpolationWithBarriers_ga(inPointFeatures, zField, outLayer, outRaster,
                                         cellSize, inBarrier, kernelFunction, bandwidth,
                                         power, ridgeParam, outputType)



Environments

Related Topics

Licensing Information

ArcView: Requires Geostatistical Analyst
ArcEditor: Requires Geostatistical Analyst
ArcInfo: Requires Geostatistical Analyst

6/24/2013