NAME

       ogr_layer_algebra - Performs various Vector layer algebraic operations

       New in version 3.6.

SYNOPSIS

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

       --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  data set path for the operation to be performed.  For operations involving 2 datasets, this
              is one of the dataset.

       -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

       1998-2024

                                                  Feb 08, 2024                              OGR_LAYER_ALGEBRA(1)