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:

              • 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 common 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 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

                                                  Feb 11, 2025                              OGR_LAYER_ALGEBRA(1)