Geoprocessing tool reference > Data Management toolbox > Projections and Transformations toolset > Tools
Create Custom Geographic Transformation (Data Management) |
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Release 9.2
Last modified November 29, 2010 |
Print all topics in : "Tools" |
Creates a transformation method for converting data between two geographic coordinate systems or datums. The output of this tool can be used as a transformation method for any tool with a parameter that requires such a method.
Usage tips
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All custom geographic transformation files are saved with a *.gtf extension.
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Custom transformation files can't be edited. They are binary files that store version and string length information that may be corrupted if edited outside of the geoprocessing framework. To update the file you should create a new custom geographic transformation and overwrite the existing file.
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All custom geographic transformations are stored in the users Documents and Settings folder: ...\\Documents and Settings\<user>\Application Data\ESRI\ArcToolbox\CustomTransformations.
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Any geoprocessing tool that uses geographic transformations will look at all custom transformations in the default storage location and present them as valid transformation options on the dialog. For example, the Project (Data Management) tool.
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For more information on geographic transformations, see Geographic transformation methods.
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For more information on equation-based transformation methods, see Equation-based methods.
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For more information on grid-based transformation methods, see Grid-based methods.
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The following environment(s) affect this tool:workspace, extent, and Output coordinate system.
Command line syntax
An overview of the Command Line window
CreateCustomGeoTransformation_management <geot_name> <in_coor_system> <out_coor_system> <custom_geot>
| Parameter | Explanation | Data Type |
| <geot_name> |
Name of the transformation method. All custom geographic transformation files are saved with a *.gtf extension and stored in the users Documents and Settings folder: ...\\Documents and Settings\<user>\Application Data\ESRI\ArcToolbox\CustomTransformations. |
String |
| <in_coor_system> |
Specify the starting geographic coordinate system. |
Coordinate System |
| <out_coor_system> |
Specify the final geographic coordinate system. |
Coordinate System |
| <custom_geot> |
Specify an existing transformation method from the drop-down list that will be used to transform the data from the input geographic coordinate system to the output geographic coordinate system. Once selected you may customize the methods values. |
String |
Command line example
CreateCustomGeoTransformation MyCustomGT1 GEOGCS['GCS_WGS_1984',DATUM['D_WGS_1984',SPHEROID['WGS_1984',6378137.0,298.257223563]],PRIMEM['Greenwich',0.0],UNIT['Degree',0.0174532925199433]] GEOGCS['GCS_Abidjan_1987',DATUM['D_Abidjan_1987',SPHEROID['Clarke_1880_RGS',6378249.145,293.465]],PRIMEM['Greenwich',0.0],UNIT['Degree',0.0174532925199433]] GEOGTRAN[METHOD['Molodensky'],PARAMETER['X_Axis_Translation',232332.0],PARAMETER['Y_Axis_Translation',2323.0],PARAMETER['Z_Axis_Translation',2323.0]]
Scripting syntax
About getting started with writing geoprocessing scripts
CreateCustomGeoTransformation_management (geot_name, in_coor_system, out_coor_system, custom_geot)
| Parameter | Explanation | Data Type |
| geot_name (Required) |
Name of the transformation method. All custom geographic transformation files are saved with a *.gtf extension and stored in the users Documents and Settings folder: ...\\Documents and Settings\<user>\Application Data\ESRI\ArcToolbox\CustomTransformations. |
String |
| in_coor_system (Required) |
Specify the starting geographic coordinate system. |
Coordinate System |
| out_coor_system (Required) |
Specify the final geographic coordinate system. |
Coordinate System |
| custom_geot (Required) |
Specify an existing transformation method from the drop-down list that will be used to transform the data from the input geographic coordinate system to the output geographic coordinate system. Once selected you may customize the methods values. |
String |
Data types for geoprocessing tool parameters
Script example
# Create the Geoprocessor Object
import arcgisscripting
gp = arcgisscripting.create()
# Set the Toolbox
GP.toolbox = "management"
# Set two spatial reference variables
InputGCS = "GEOGCS['GCS_WGS_1984',DATUM['D_WGS_1984',SPHEROID['WGS_1984',6378137.0,298.257223563]],PRIMEM['Greenwich',0.0],UNIT['Degree',0.0174532925199433]]"
OutputGCS = "GEOGCS['GCS_Abidjan_1987',DATUM['D_Abidjan_1987',SPHEROID['Clarke_1880_RGS',6378249.145,293.465]],PRIMEM['Greenwich',0.0],UNIT['Degree',0.0174532925199433]]"
# Customize the transformation method
CustomGT = "GEOGTRAN[METHOD['Molodensky'],PARAMETER['X_Axis_Translation',232332.0],PARAMETER['Y_Axis_Translation',2323.0],PARAMETER['Z_Axis_Translation',2323.0]]"
# Run tool in a try and except
try:
GP.CreateCustomGeoTransformation("MyCustomGT1", InputGCS, OutputGCS, CustomGT)
except:
print GP.GetMessages(2)