OGR_LAYER_ALGEBRA(1) GDAL OGR_LAYER_ALGEBRA(1)

NAME

ogr_layer_algebra - Performs various Vector layer algebraic
operations

New 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 specified 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:

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

+o Intersection
An intersection is a set of features, which represent the
common areas of two layers.

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

+o 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.

+o 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.

+o 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.

+o 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
operations 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
performed ( 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 performed ( Optional )

-output_ds <path>
Output data set path for writing the result of the operations
performed 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 generated 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
output 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 output layer , if eligible according to the operation.

-nlt <geom_type>
Define the geometry type for the created layer. One of NONE,
GEOMETRY, 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 declarations, or
the name of a .prj file containing a WKT CRS definition.

COPYRIGHT

1998-2025

January 8, 2025 OGR_LAYER_ALGEBRA(1)