v.select1grass

OVERLAP: features partially or completely overlap (using GRASS)

Select grid boxes (North Carolina sample dataset):

d.vect map=zipcodes_wake fill_color=0:128:0
d.vect map=boxgrid fill_color=85:130:176
v.select ainput=boxgrid binput=zipcodes_wake output=v_select_OVERLAP operator=overlap
d.vect map=v_select_OVERLAP
d.vect map=zipcodes_wake type=boundary color=255:255:50

v.select with OVERLAP operator: selected grid boxes shown in yellow (using GRASS method)

OVERLAPS features spatially overlap (using GEOS)

Select grid boxes (North Carolina sample dataset):

d.vect map=zipcodes_wake fill_color=0:128:0
d.vect map=boxgrid fill_color=85:130:176
v.select ainput=boxgrid binput=zipcodes_wake output=v_select_OVERLAPS operator=overlaps
d.vect map=v_select_OVERLAPS
d.vect map=zipcodes_wake type=boundary color=255:255:50

v.select with OVERLAPS operator: selected grid boxes shown in yellow (using GEOS method)

DISJOINT: features do not spatially intersect (using GEOS)

Select grid boxes (North Carolina sample dataset):

d.vect map=zipcodes_wake fill_color=0:128:0
d.vect map=boxgrid fill_color=85:130:176
v.select ainput=boxgrid binput=zipcodes_wake output=v_select_DISJOINT operator=disjoint
d.vect map=v_select_DISJOINT
d.vect map=zipcodes_wake type=boundary color=255:255:50

v.select with DISJOINT operator: selected grid boxes shown in yellow

EQUALS: features are spatially equals (using GEOS)

Select zipcode polygon (North Carolina sample dataset):

d.vect map=zipcodes_wake fill_color=0:128:0
v.extract input=zipcodes_wake where=ZIPCODE_ID=35 output=zipcodeID35
v.select ainput=zipcodes_wake binput=zipcodeID35 output=v_select_EQUALS operator=equals
d.vect map=v_select_EQUALS
d.vect map=zipcodes_wake type=boundary color=255:255:50

v.select with EQUALS operator: selected grid boxes shown in yellow

INTERSECTS: features spatially intersect (using GEOS)

Select zipcode polygons (North Carolina sample dataset):

d.vect map=zipcodes_wake fill_color=0:128:0
d.vect map=boxgrid fill_color=85:130:176
v.select ainput=zipcodes_wake binput=boxgrid output=v_select_INTERSECTS operator=intersects
d.vect map=v_select_INTERSECTS
d.vect map=boxgrid type=boundary color=255:255:50

v.select with INTERSECTS operator: selected grid boxes shown in yellow

TOUCHES: features spatially touches (using GEOS)

Select polygons (North Carolina sample dataset):

d.vect map=zipcodes_wake fill_color=0:128:0
d.vect map=zipcodeID35 fill_color=85:130:176
v.select ainput=zipcodes_wake binput=zipcodeID35 output=v_select_TOUCHES operator=touches
d.vect map=v_select_TOUCHES
d.vect map=zipcodes_wake type=boundary color=255:255:50

v.select with TOUCHES operator: selected polygons shown in yellow (blue: input polygon)

CROSSES: features spatially crosses (using GEOS)

Select zipcode polygons by lines (North Carolina sample dataset):

d.vect map=zipcodes_wake fill_color=0:128:0
d.vect map=busroute1 color=200:27:27 width=3
v.select ainput=zipcodes_wake binput=busroute1 output=v_select_CROSSES operator=crosses
d.vect map=v_select_CROSSES
d.vect map=zipcodes_wake type=boundary color=255:255:50
d.vect map=busroute1 color=200:27:27 width=3

v.select with CROSSES operator: selected polygons shown in yellow (red: input lines)

WITHIN feature A is completely inside feature B (using GEOS)

Select zipcode polygons (North Carolina sample dataset):

d.vect map=zipcodes_wake fill_color=0:128:0
d.vect map=boundary_county fill_color=85:130:176
v.select ainput=zipcodes_wake binput=boundary_county output=v_select_WITHIN operator=within
d.vect map=v_select_WITHIN

v.select with WITHIN operator: selected polygons shown in yellow (blue: input polygons)

CONTAINS feature B is completely inside feature A (using GEOS)

Select zipcode polygon (North Carolina sample dataset):

CONTAINS with polygons

d.vect map=zipcodes_wake fill_color=0:128:0
d.vect map=zipcodeID35 fill_color=85:130:176
v.select ainput=zipcodes_wake binput=zipcodeID35 \
         output=v_select_CONTAINS_pol operator=contains
d.vect map=v_select_CONTAINS

v.select with CONTAINS operator: selected polygon shown in yellow (blue: input polygon, not visible)

CONTAINS with points

d.vect map=zipcodes_wake fill_color=0:128:0
d.vect map=hospitals fill_color=195:31:31 icon=basic/cross3 size=10
v.select ainput=zipcodes_wake binput=hospitals \
         output=v_select_CONTAINS_pnts operator=contains
d.vect map=v_select_CONTAINS_pnts
d.vect map=hospitals fill_color=195:31:31 icon=basic/cross3 size=10

v.select with CONTAINS operator: selected polygons shown in yellow (red: input points)

RELATE feature A is spatially related to feature B (using GEOS)

This operator additionally requires the relate parameter (in other GIS called ’ST_Relate’). This operator allows calculating the Dimensionally Extended nine-Intersection Model (DE-9IM). In the following one example: Select polygon with ’TOUCHES’ operator (North Carolina sample dataset):

d.vect map=zipcodes_wake fill_color=0:128:0
d.vect map=zipcodeID35 fill_color=85:130:176
v.select ainput=zipcodeID35 binput=zipcodes_wake \
         output=v_select_TOUCHES_relate operator=relate relate=’T********’
d.vect map=v_select_TOUCHES

The result of relate=’T********’ is the same as seen above in the example ’TOUCHES’. See the DE-9IM page for related operators and their definition.

Extraction of points falling into a polygon

Extract fire stations (points) falling into urban area (polygon) - North Carolina data set (point in polygon test):

v.select ainput=firestations binput=urbanarea output=urban_firestations \
         operator=overlap

Extraction of lines overlapping with a polygon

Extract railroad lines from zip code map overlapping with the urban area (line in polygon test):

v.select ainput=railroads binput=urbanarea \
         output=railroads_in_urbanarea operator=overlap

Extraction of areas overlapping with a line

Extract those areas from zip code map which overlap with railroads (polygon on line test):

# first add a tiny buffer around railroad lines:
v.buffer input=railroads output=railroads_buf20m \
  distance=20
v.select ainput=zipcodes_wake binput=railroads_buf20m \
  output=zipcodes_wake_railroads operator=overlap