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OGR_LAYER_ALGEBRA(1)		      GDAL		    OGR_LAYER_ALGEBRA(1)

NAME
     ogr_layer_algebra - Performs various Vector layer algebraic operations

     Added in version 3.6.

SYNOPSIS
	ogr_layer_algebra [--help] [--help-general]
			    Union|Intersection|SymDifference|Identity|Update|Clip|Erase
			    -input_ds <path> [-input_lyr <name>]
			    -method_ds <path> [-method_lyr <name>]
			    -output_ds <path> [-output_lyr <name>] [-overwrite]
			    [-opt <NAME>=<VALUE>]...
			    [-f <format_name>] [-dsco <NAME>=<VALUE>]... [-lco <NAME>=<VALUE>]...
			    [-input_fields {NONE|ALL|<fld1>,<fl2>,...<fldN>}] [-method_fields {NONE|ALL|<fld1>,<fl2>,...<fldN>}]
			    [-nlt <geom_type>] [-a_srs <srs_def>]

DESCRIPTION
     The  ogr_layer_algebra  provides  a command line utility to perform various
     vector layer algebraic operations. The utility takes a vector input  source
     and a method source and generates the output of the operation in the speci-
     fied output file.

     NOTE:
	ogr_layer_algebra  is  a  Python  utility, and is only available if GDAL
	Python bindings are available.

     --help
	    Show this help message and exit

     --help-general
	    Gives a brief usage message for the generic GDAL commandline options
	    and exit.

     <mode>
	    Where <mode> is one of the seven available modes:

	    * Union
		 A union is a set of features, which represent areas that are in
		 either of the operand layers.

	    * Intersection
		 An intersection is a set of features, which represent the  com-
		 mon areas of two layers.

	    * SymDifference
		 A  symmetric  difference  is a set of features, which represent
		 areas that are in operand layers but which do not intersect.

	    * Identity
		 The identity method identifies features in the input layer with
		 features in the method layer possibly splitting  features  into
		 several  features.   By default the result layer has attributes
		 from both operand layers.

	    * Update
		 The update method creates a layer, which add features into  the
		 input	layer from the method layer possibly cutting features in
		 the input layer.  By default the result  layer  has  attributes
		 only from the input layer.

	    * Clip
		 The  clip  method  creates a layer, which has features from the
		 input layer clipped to the areas of the features in the  method
		 layer.  By default the result layer has attributes of the input
		 layer.

	    * Erase
		 The  erase  method creates a layer, which has features from the
		 input layer whose areas are  erased  by  the  features  in  the
		 method  layer.   By  default the result layer has attributes of
		 the input layer.

     -input_ds <path>
	    Input dataset path for the operation to be	performed.   For  opera-
	    tions involving two datasets, this is one of the datasets.

     -input_lyr <name>
	    Layer  name of the input_ds for which the operations have to be per-
	    formed ( Optional )

     -method_ds <path>
	    Method data set path for the operation to  be  performed.	This  is
	    usually  the  conditional  data  set supplied to the operation ( ex:
	    clip , erase , update ) This is the Second data set in the operation
	    ( ex : Union, Intersection , SymDifference )

     -method_lyr <name>
	    Layer name of the method_ds for which the operations have to be per-
	    formed ( Optional )

     -output_ds <path>
	    Output data set path for writing the result of the	operations  per-
	    formed by ogr_layer_algebra.

     -output_lyr_name <name>
	    Layer  name of the output_lyr_name where the output vector has to be
	    written. ( Optional )

     -overwrite
	    Indicates whether the output_ds have to be overwritten with the gen-
	    erated result of ogr_layer_algebra.

     -opt <NAME>=<VALUE>
	    Attributes for which the  operation  has  to  run  on  input_ds  and
	    method_ds.

     -f <format_name>
	    Select  the  output  format.If  not specified, the format is guessed
	    from the extension (previously was ESRI Shapefile).  Use  the  short
	    format name

     -dsco <NAME>=<VALUE>
	    Dataset creation option (format specific).

     -lco <NAME>=<VALUE>
	    Layer creation option (format specific).

     -input_fields {NONE|ALL|<fld1>,<fl2>,...<fldN>}
	    Comma-delimited  list of fields from input layer to copy to the out-
	    put layer , if eligible according to the operation.

     -method_fields {NONE|ALL|<fld1>,<fl2>,...<fldN>}
	    Comma-delimited list of fields from method layer to copy to the out-
	    put layer , if eligible according to the operation.

     -nlt <geom_type>
	    Define the geometry type for the created layer.  One of NONE, GEOME-
	    TRY, POINT,  LINESTRING,  POLYGON,	GEOMETRYCOLLECTION,  MULTIPOINT,
	    MULTIPOLYGON,   GEOMETRY25D,  POINT25D,  LINESTRING25D,  POLYGON25D,
	    GEOMETRYCOLLECTION25D, MULTIPOINT25D, MULTIPOLYGON25D.

     -a_srs <srs_def>
	    Assign an output SRS, but without reprojecting

	    The coordinate reference systems that can  be  passed  are	anything
	    supported  by the OGRSpatialReference.SetFromUserInput() call, which
	    includes  EPSG  Projected,	Geographic   or   Compound   CRS   (i.e.
	    EPSG:4296),  a well known text (WKT) CRS definition, PROJ.4 declara-
	    tions, or the name of a .prj file containing a WKT CRS definition.

COPYRIGHT
     1998-2025

				  Oct 29, 2025		    OGR_LAYER_ALGEBRA(1)

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