Union
A Union operation is a special kind of union. It calculates the intersection
between the Input Layer
(A) and Overlay Layer
(B) by generating a geometry for each intersection, calculates the
difference between A and B, and also calculates the difference
between B
and A. All geometries generated by these three steps will be part
of
the result.
The attributes from A and B
can
be selected to compose the result. The geometries generated by the
intersection will have values for all attributes selected by A and
B.
The geometries
generated by the difference between A and B will have values
only
for the attributes originally from A, and the geometries
generated
by the difference between B and A will have values only for
the
attributes originally from B.
It is
accessed through:
Processing > Vector
Processing > Union...
- Input Layer (A): select one layer from the list
: Optionally, check this option
if you wish to process UNION only the previously selected objects in the map display.
: Optionally, choose which attributes from layer (A) will be part of the output layer.
- Overlay layer (B): select layer B to compute the
union with.
- : Optionally, check this option
if you wish to process UNION only the previously selected objects in the map display.
- : Optionally, choose which attributes from layer (B) will be part of the output layer.
- Output Object Type:
default is Single objects,
meaning it will generate simple geometries. Multi Objects means the
geometries can be grouped (MultiGeometry).
- Output Repository: inform the repository by
clicking on:
to
select the output directory
and also inform the new layer name to store the result, or
to
select the output Data
Source (giving
its connection parameters).- Layer Name: inform the
new layer name to store the result at the data source.
- Click OK to perform the operation or Cancel to
close the interface.