Gaussian Geostatistical Simulations (Geostatisical Analyst)

License Level:BasicStandardAdvanced

Summary

Performs a conditional or unconditional geostatistical simulation based on a Simple Kriging model.

Usage

Syntax

GaussianGeostatisticalSimulations_ga (in_geostat_layer, number_of_realizations, output_workspace, output_simulation_prefix, {in_conditioning_features}, {conditioning_field}, {conditioning_measurement_error_field}, {cell_size}, {in_bounding_dataset}, {save_simulated_rasters}, {quantile}, {threshold}, {in_stats_polygons}, {raster_stat_type})
ParameterExplanationData Type
in_geostat_layer

Input a geostatistical layer resulting from a Simple Kriging model.

Geostatistical Layer
number_of_realizations

The number of simulations to perform.

Long
output_workspace

Stores all the simulation results.

Workspace
output_simulation_prefix

A 1- to 3-character alphanumeric prefix that is automatically added to the output dataset names.

String
in_conditioning_features
(Optional)

The features used to condition the realizations. If left blank, unconditional realizations are produced.

Feature Layer
conditioning_field
(Optional)

The field used to condition the realizations. If left blank, unconditional realizations are produced.

Field
conditioning_measurement_error_field
(Optional)

Specifies a constant measurement error for all input data in the input semivariogram model. Use this field if the measurement error values are not the same at each sampling location. The input's unit of measurement is applied.

Leave this blank if there are no measurement error values.

Field
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_bounding_dataset
(Optional)

Limits the analysis to these features' bounding polygon. If point features are entered, then a convex hull polygon is automatically created. Realizations are then performed within that polygon. If bounding features are supplied, any features or rasters supplied in the Mask environment will be ignored.

Feature Layer
save_simulated_rasters
(Optional)

Specifies whether or not the simulated rasters are saved to disk.

  • TRUEIndicates that the simulated rasters will be saved to disk.
  • FALSEIndicates that the simulated rasters will not be saved to disk.
Boolean
quantile
(Optional)

The quantile value for which the output raster will be generated.

Double
threshold
(Optional)

The threshold value for which the output raster will be generated, as the percentage of the number of times the set threshold was exceeded, on a cell-by-cell basis.

Double
in_stats_polygons
(Optional)

These polygons represent areas of interest for which summary statistics are calculated.

Feature Layer
raster_stat_type
[raster_stat_type,...]
(Optional)

The simulated rasters are postprocessed on a cell-by-cell basis, and each selected statistics type is calculated and reported in an output raster.

  • MINCalculates the minimum (smallest value)
  • MAXCalculates the maximum (largest value)
  • MEANCalculates the mean (average)
  • STDDEVCalculates the standard deviation
  • QUARTILE1Calculates the 25th quantile
  • MEDIANCalculates the median
  • QUARTILE3Calculates the 75th quantile
  • QUANTILECalculates a user-specified quantile (0 < Q < 1)
  • P_THRSHLDCalculates the percentage of the simulations where the cell value exceeds a user-specified threshold value
String

Code Sample

GaussianGeostatisticalSimulations example 1 (Python window)

Perform an unconditional simulation.

import arcpy
arcpy.env.workspace = "C:/gapyexamples/data"
arcpy.GaussianGeostatisticalSimulations_ga("C:/gapyexamples/data/kriging.lyr", "10",
                                           "C:/gapyexamples/output", "ggs", "", "",
                                           "2000", "", "", "", "", "", "MEAN")
GaussianGeostatisticalSimulations example 2 (stand-alone script)

Perform an unconditional simulation.

# Name: GaussianGeostatisticalSimulations_Example_02.py
# Description: This tool performs conditional or unconditional geostatistical
#              simulation based on a Simple Kriging model.
# 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"
numRealizations = 10
outWorkspace = "C:/gapyexamples/output"
cellSize = 2000
prefix = "ggs"
rasstatType = "MEAN"
conFeatures = ""
conField = ""
boundingData = ""
savesimRasters = ""
quantile = ""
threshold = ""
statsPolygons = ""
errorField = ""

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

# Execute GaussianGeostatisticalSimulations
arcpy.GaussianGeostatisticalSimulations_ga(
    inLayer, numRealizations, outWorkspace, prefix, conFeatures, conField, 
    cellSize, boundingData, savesimRasters, quantile, threshold, 
    statsPolygons, rasstatType, errorField)

Environments

Related Topics

Licensing Information

ArcGIS for Desktop Basic: Requires Geostatistical Analyst
ArcGIS for Desktop Standard: Requires Geostatistical Analyst
ArcGIS for Desktop Advanced: Requires Geostatistical Analyst
3/7/2014