ArcMap

GA Layer To Points

Available with Geostatistical Analyst license.

Summary

Exports a geostatistical layer to points. The tool can also be used to predict values at unmeasured locations or to validate predictions made at measured locations.

Usage

  • For data formats that support Null values, such as file geodatabase feature classes, a Null value will be used to indicate that a prediction could not be made for that location or that the value should be ignored when used as input. For data formats that do not support Null values, such as shapefiles, the value of -1.7976931348623158e+308 is used (this is the negative of the C++ defined constant DBL_MAX) to indicate that a prediction could not be made for that location.

  • If a validation z-field is supplied, the predictions and standard errors are calculated differently than if a validation field is not supplied. For more information, see the following reference:

    • Krivoruchko, K., A. Gribov, and J. M. Ver Hoef, 2006, "A new method for handling the nugget effect in kriging," T. C. Coburn, J. M. Yarus, and R. L. Chambers, Eds., Stochastic modeling and geostatistics: Principles, methods, and case studies, volume II: AAPG Computer Applications and Geology 5, p. 81–89.

Syntax

arcpy.ga.GALayerToPoints(in_geostat_layer, in_locations, {z_field}, out_feature_class, {append_all_fields})
ParameterExplanationData Type
in_geostat_layer

The geostatistical layer to be analyzed.

Geostatistical Layer
in_locations

Point locations where predictions or validations will be performed.

Feature Layer
z_field
(Optional)

If this field is left blank, predictions are made at the location points. If a field is selected, predictions are made at the location points, compared to their Z_value_field values, and a validation analysis is performed.

Field
out_feature_class

The output feature class containing either the predictions or the predictions and the validation results.

The fields in this feature class can include the following fields (where applicable):

  • Source_ID (Source ID)—The object ID of the source feature in the Input point observation locations.
    • The feature or object identifier of the input dataset that was used.
  • Included (Included)—Indicates whether a prediction was calculated for this feature. The values in this field can be one of the following:
    • Yes—There are no problems making a prediction at this point.
    • Not enough neighbors—There are not enough neighbors to make a prediction.
    • Weight parameter is too small—The weight parameter is too small.
    • Overfilling—Overflow of floating-point calculations.
    • Problem with data transformation—The value to be transformed is outside of the supported range for the selected transformation (only in kriging).
  • Predicted (Predicted)—The prediction value at this location.
  • Error (Error)—The predicted value minus the value in the validation field.
  • StdError (Standard Error)—The kriging standard error.
  • Stdd_Error (Standardized Error)—The standardized prediction errors. Ideally, the standardized prediction errors are distributed normally.
  • NormValue (Normal Value)—The normal distribution value (x-axis) that corresponds to the standardized prediction errors (y-axis) in the normal QQplot.
Feature Class
append_all_fields
(Optional)

Determines whether all fields will be copied from the input features to the output feature class.

  • ALL — All fields from the input features will be copied to the output feature class. This is the default.
  • FID_ONLY — Only the feature ID will be copied, and it will be named Source_ID on the output feature class.
Boolean

Code sample

GALayerToPoints example 1 (Python window)

Export a geostatistical layer to a point feature class.

import arcpy
arcpy.env.workspace = "C:/gapyexamples/data"
arcpy.GALayerToPoints_ga("C:/gapyexamples/data/kriging.lyr", 
                         "C:/gapyexamples/data/obs_pts.shp",                   
                         "", "C:/gapyexamples/output/krig_pts")
GALayerToPoints example 2 (stand-alone script)

Export a geostatistical layer to a point feature class.

# Name: GALayerToPoints_Example_02.py
# Description: Exports a geostatistical layer to points.
# Requirements: Geostatistical Analyst Extension

# Import system modules
import arcpy

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

# Set local variables
inLayer = "C:/gapyexamples/data/kriging.lyr"
inPoints = "C:/gapyexamples/data/obs_pts.shp"
zField = ""
outPoints = "C:/gapyexamples/output/krig_pts"

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

# Execute GALayerToPoints
arcpy.GALayerToPoints_ga(inLayer, inPoints, zField, outPoints)

Environments

Licensing information

  • Basic: Requires Geostatistical Analyst
  • Standard: Requires Geostatistical Analyst
  • Advanced: Requires Geostatistical Analyst

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