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
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The Absolute feature barrier employs a “non Euclidean” distance approach rather than a “line of sight” approach. The “line of sight” approach requires that a straight line between the measured location and the location where the prediction is required do not intersect the barrier feature. If the distance around the barrier is within the searching neighborhood specifications, then it will be considered in this “non Euclidean” distance approach.
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The processing time is dependent on the complexity of the barrier feature classes geometry. Tools in the Generalization toolset can be used to create a new feature class by smoothing or deleting some of these features.
For EXPONENTIAL, GAUSSIAN, and CONSTANT kernel functions, a smoothing factor is applied so that the kernels have a finite radius that is equal to the specified bandwidth.
Syntax
| Parameter | Explanation | Data 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.
| 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.
| String |
Code Sample
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")
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)