Semivariogram Sensitivity (Geostatisical Analyst)
Summary
Performs a sensitivity analysis with varying Nugget, Partial Sill, and Range values.
Usage
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The geostatistical model source is either a geostatistical layer or a geostatistical model (XML).
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Set the environment variable Seed equal to a nonzero value if the random sequence should be repeatable.
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For data formats that support Null values, such as file and personal 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 showed 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.
Syntax
| Parameter | Explanation | Data Type |
in_ga_model_source |
The geostatistical model source to be analyzed. | File; Geostatistical Layer |
in_datasets [in_dataset,...] |
Input datasets displays two pieces:
| Geostatistical Value Table |
in_locations |
Point locations where the sensitivity analysis is performed. | Feature Layer |
nugget_span_percents (Optional) |
The percentage subtracted and added to the Nugget parameter to create a range for subsequent random Nugget parameter selection. | Double |
nugget_calc_times (Optional) |
Number of random Nugget values drawn from the Nugget span. | Long |
partialsill_span_percents (Optional) |
Percentage subtracted from and added to the Partial Sill parameter to create a range for random Partial Sill selection. | Double |
partialsill_calc_times (Optional) |
Number of random Partial Sill values drawn from the Partial Sill span. | Long |
range_span_percents (Optional) |
Percentage subtracted and added to the Major Range parameter to create a range for a random Major Range selection. | Double |
range_calc_times (Optional) |
Number of random Major Range values drawn from the Major Range span. | Long |
minrange_span_percents (Optional) |
Percentage subtracted and added to the Minor Range parameter to create a range for random Minor Range selection. | Double |
minrange_calc_times (Optional) |
Number of random Minor Range values drawn from the Minor Range span. If Anisotropy has been set in <in_geostat_layer>, a value is required. | Long |
out_table |
Table storing the sensitivity results. | Table |
Code Sample
Performs a sensitivity analysis by varying the Nugget, Partial Sill, and Range values.
import arcpy
arcpy.env.workspace = "C:/gapyexamples/data"
arcpy.GASemivariogramSensitivity_ga(
"C:/gapyexamples/data/kriging.lyr", "C:/gapyexamples/data/ca_ozone_pts.shp OZONE",
"C:/gapyexamples/data/obs_pts.shp", "", "", "", "", "", "", "", "",
"C:/gapyexamples/output/outtabSS")
Performs a sensitivity analysis by varying the Nugget, Partial Sill, and Range values.
# Name: SemivariogramSensitivity_Example_02.py
# Description: The semivariogram parameters Nugget, Partial Sill and Range can
# be varied to perform a sensitivity analysis.
# 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"
inData = "C:/gapyexamples/data/ca_ozone_pts.shp OZONE"
inObs = "C:/gapyexamples/data/obs_pts.shp"
nugPercents = ""
nugCalc = ""
sillPercents = ""
sillCalc = ""
rangePercents = ""
rangeClac = ""
minrangePercent = ""
midrangeCalc = ""
outTable = "C:/gapyexamples/output/outtabSS"
# Check out the ArcGIS Geostatistical Analyst extension license
arcpy.CheckOutExtension("GeoStats")
# Execute SemivariogramSensitivity
arcpy.GASemivariogramSensitivity_ga(inLayer, inData, inObs, nugPercents, nugCalc,
sillPercents, sillCalc, rangePercents, rangeClac,
minrangePercent, midrangeCalc, outTable)