NAME

       ogr_layer_algebra - Performs various Vector layer algebraic operations

       New in version 3.6.

SYNOPSIS

          ogr_layer_algebra.py Union|Intersection|SymDifference|Identity|Update|Clip|Erase
                              -input_ds name [-input_lyr name]
                              -method_ds [-method_lyr name]
                              -output_ds name [-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

       <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,fld2,fld3...>
              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,fld2,fld3...>
              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

       1998-2023

                                           Jan 02, 2023                      OGR_LAYER_ALGEBRA(1)