Map classes

Occupancy grid classes

Binary Occupancy grid

class roboticstoolbox.mobile.BinaryOccupancyGrid(grid=None, **kwargs)[source]

Bases: BaseOccupancyGrid

__init__(grid=None, **kwargs)[source]

Create a binary occupancy grid instance

Parameters:

grid (ndarray(N,M)) – occupancy grid as a NumPy array
size (float, optional) – cell size, defaults to 1
origin (array_like(2), optional) – world coordinates of the grid element [0,0], defaults to (0, 0)
kwargs – options passed to BaseMap

The array is kept internally as a bool array. Cells are set to True (occupied) corresponding to input values > 0.

This object supports a user-defined coordinate system and grid size. World coordinates are converted to grid coordinates to lookup the occupancy status.

Example:

>>> from roboticstoolbox import BinaryOccupancyGrid
>>> import numpy as np
>>> og = BinaryOccupancyGrid(np.zeros((5,5)))
>>> print(og)
BinaryOccupancyGrid: 5 x 5, cell size=1, x = [0.0, 4.0], y = [0.0, 4.0], 0.0% occupied
>>> og = BinaryOccupancyGrid(workspace=[-5,5], cellsize=0.1, value=0)
>>> print(og)
BinaryOccupancyGrid: 101 x 101, cell size=0.1, x = [-5.0, 5.0], y = [-5.0, 5.0], 0.0% occupied

Seealso:: OccupancyGrid

isoccupied(p)[source]

Test if coordinate is occupied

Parameters:: p (array_like(2)) – world coordinate (x, y)
Returns:: occupancy status of corresponding grid cell
Return type:: bool

The grid cell size and offset are used to convert p to an occupancy grid coordinate. The grid coordinate is rounded and cast to integer value. If the coordinate is outside the bounds of the occupancy grid it is considered to be occupied.

Seealso:: w2g()

inflate(radius)[source]

Inflate obstales

Parameters:: radius (float) – radius of circular structuring element in world units

A circular structuring element is created and used to dilate the stored occupancy grid.

Successive calls to inflate will compound the inflation.

Seealso:: scipy.ndimage.binary_dilation()

copy()

Copy an occupancy grid (superclass)

Returns:: copy of the ocupancy grid
Return type:: OccGrid

g2w(p)

Convert grid coordinate to world coordinate (superclass)

Parameters:: p (array_like(2)) – grid coordinate (column, row)
Returns:: world coordinate (x, y)
Return type:: ndarray(2)

The grid cell size and offset are used to convert occupancy grid coordinate p to a world coordinate.

property grid

Occupancy grid as a NumPy array (superclass)

Returns:: binary occupancy grid
Return type:: ndarray(N,M) of bool

If inflate() has been called, this will return the inflated occupancy grid.

line_w(p1, p2)

Get index of cells along a line segment (superclass)

Parameters:

p1 (array_like(2)) – start
p2 (array_like(2)) – end

Returns:

index into grid

Return type:

ndarray(N)

Get the indices of cells along a line segment defined by the end points given in world coordinates.

The returned indices can be applied to a raveled view of the grid.

Seealso:: ravel() w2g()

property maxdim

Maximum dimension of grid in world coordinates (superclass)

Returns:: maximum side length of the occupancy grid
Return type:: float

property name

Occupancy grid name (superclass)

Returns:: name of the occupancy grid
Return type:: str

plot(map=None, ax=None, block=None, **kwargs)

Plot the occupancy grid (superclass)

Parameters:

map (ndarray(N,M), optional) – array which is plotted instead of the grid, must be same size as the occupancy grid,defaults to None
ax (Axes2D, optional) – matplotlib axes to plot into, defaults to None
block (bool, optional) – block until plot is dismissed, defaults to None
kwargs – arguments passed to imshow

The grid is plotted as an image but with axes in world coordinates.

The grid is a NumPy boolean array which has values 0 (false=unoccupied) and 1 (true=occupied). Passing a cmap option to imshow can be used to control the displayed color of free space and obstacles.

property ravel

Ravel the grid (superclass)

Returns:: 1D view of the occupancy grid
Return type:: ndarray(N)

set(region, value)

Set region of map (superclass)

Parameters:

region (array_like(4)) – The region [xmin, ymin, xmax, ymax]
value (int, bool, float) – value to set cells to

property shape

Shape of the occupancy grid array (superclass)

Returns:: shape of the occupancy grid array
Return type:: 2-tuple

This is the shape of the NumPy array that holds the occupancy grid.

w2g(p)

Convert world coordinate to grid coordinate (superclass)

Parameters:: p (array_like(2)) – world coordinate (x, y)
Returns:: grid coordinate (column, row)
Return type:: ndarray(2)

The grid cell size and offset are used to convert p to an occupancy grid coordinate. The grid coordinate is rounded and cast to integer value. No check is made on the validity of the coordinate.

property workspace

Bounds of the occupancy grid in world coordinates (superclass)

Returns:: workspace bounds [xmin, xmax, ymin, ymax]
Return type:: ndarray(4)

Returns the bounds of the occupancy grid in world coordinates.

property xmax

Maximum x-coordinate of this grid (superclass)

Returns:: maximum world x-coordinate
Return type:: float

property xmin

Minimum x-coordinate of this grid (superclass)

Returns:: minimum world x-coordinate
Return type:: float

property ymax

Maximum y-coordinate of this grid (superclass)

Returns:: maximum world y-coordinate
Return type:: float

property ymin

Minimum y-coordinate of this grid (superclass)

Returns:: minimum world y-coordinate
Return type:: float

Occupancy grid

class roboticstoolbox.mobile.OccupancyGrid(grid=None, origin=(0, 0), value=0, cellsize=1, **kwargs)[source]

Bases: BaseOccupancyGrid

General occupancy grid

The elements of the array are floats and can represent occupancy probability or traversal cost.

Example:

>>> from roboticstoolbox import OccupancyGrid
>>> import numpy as np
>>> og = OccupancyGrid(np.zeros((5,5)))
>>> print(og)
OccupancyGrid: 5 x 5, cell size=1, x = [0.0, 4.0], y = [0.0, 4.0], dtype float64, min 0.0, max 0.0, mean 0.0
>>> og = OccupancyGrid(workspace=[-5,5], cellsize=0.1, value=0.5)
>>> print(og)
OccupancyGrid: 101 x 101, cell size=0.1, x = [-5.0, 5.0], y = [-5.0, 5.0], dtype float64, min 0.5, max 0.5, mean 0.5

Seealso:: BinaryOccupancyGrid

__init__(grid=None, origin=(0, 0), value=0, cellsize=1, **kwargs)

Occupancy grid (superclass)

Parameters:

grid (ndarray(N,M)) – occupancy grid as a NumPy array
value (any, optional) – initial value of cells
origin (array_like(2), optional) – world coordinates of the grid element [0,0], defaults to (0, 0)
cellsize (float, optional) – cell size, defaults to 1
kwargs – options passed to BaseMap

This object supports a user-defined coordinate system and grid size. World coordinates are converted to grid coordinates to lookup the occupancy status.

The grid can be initialized by:

a 2D NumPy array
specifying workspace and value arguments

copy()

Copy an occupancy grid (superclass)

Returns:: copy of the ocupancy grid
Return type:: OccGrid

g2w(p)

Convert grid coordinate to world coordinate (superclass)

Parameters:: p (array_like(2)) – grid coordinate (column, row)
Returns:: world coordinate (x, y)
Return type:: ndarray(2)

The grid cell size and offset are used to convert occupancy grid coordinate p to a world coordinate.

property grid

Occupancy grid as a NumPy array (superclass)

Returns:: binary occupancy grid
Return type:: ndarray(N,M) of bool

If inflate() has been called, this will return the inflated occupancy grid.

line_w(p1, p2)

Get index of cells along a line segment (superclass)

Parameters:

p1 (array_like(2)) – start
p2 (array_like(2)) – end

Returns:

index into grid

Return type:

ndarray(N)

Get the indices of cells along a line segment defined by the end points given in world coordinates.

The returned indices can be applied to a raveled view of the grid.

Seealso:: ravel() w2g()

property maxdim

Maximum dimension of grid in world coordinates (superclass)

Returns:: maximum side length of the occupancy grid
Return type:: float

property name

Occupancy grid name (superclass)

Returns:: name of the occupancy grid
Return type:: str

plot(map=None, ax=None, block=None, **kwargs)

Plot the occupancy grid (superclass)

Parameters:

map (ndarray(N,M), optional) – array which is plotted instead of the grid, must be same size as the occupancy grid,defaults to None
ax (Axes2D, optional) – matplotlib axes to plot into, defaults to None
block (bool, optional) – block until plot is dismissed, defaults to None
kwargs – arguments passed to imshow

The grid is plotted as an image but with axes in world coordinates.

The grid is a NumPy boolean array which has values 0 (false=unoccupied) and 1 (true=occupied). Passing a cmap option to imshow can be used to control the displayed color of free space and obstacles.

property ravel

Ravel the grid (superclass)

Returns:: 1D view of the occupancy grid
Return type:: ndarray(N)

set(region, value)

Set region of map (superclass)

Parameters:

region (array_like(4)) – The region [xmin, ymin, xmax, ymax]
value (int, bool, float) – value to set cells to

property shape

Shape of the occupancy grid array (superclass)

Returns:: shape of the occupancy grid array
Return type:: 2-tuple

This is the shape of the NumPy array that holds the occupancy grid.

w2g(p)

Convert world coordinate to grid coordinate (superclass)

Parameters:: p (array_like(2)) – world coordinate (x, y)
Returns:: grid coordinate (column, row)
Return type:: ndarray(2)

The grid cell size and offset are used to convert p to an occupancy grid coordinate. The grid coordinate is rounded and cast to integer value. No check is made on the validity of the coordinate.

property workspace

Bounds of the occupancy grid in world coordinates (superclass)

Returns:: workspace bounds [xmin, xmax, ymin, ymax]
Return type:: ndarray(4)

Returns the bounds of the occupancy grid in world coordinates.

property xmax

Maximum x-coordinate of this grid (superclass)

Returns:: maximum world x-coordinate
Return type:: float

property xmin

Minimum x-coordinate of this grid (superclass)

Returns:: minimum world x-coordinate
Return type:: float

property ymax

Maximum y-coordinate of this grid (superclass)

Returns:: maximum world y-coordinate
Return type:: float

property ymin

Minimum y-coordinate of this grid (superclass)

Returns:: minimum world y-coordinate
Return type:: float

Polygon map

class roboticstoolbox.mobile.PolygonMap(workspace=None, polygons=[])[source]

Bases: BaseMap

__init__(workspace=None, polygons=[])[source]

Polygonal obstacle map

Parameters:

workspace (float, array_like(2), array_like(4)) – dimensions of 2D plot area, defaults to (-10:10) x (-10:10), see plotvol2()
polygons (list, optional) – obstacle polygons, defaults to []

The obstacle polygons are specified as instances of Polygon2 or ndarray(2,N).

The workspace can be specified in several ways:

`workspace`	x-range	y-range
A (scalar)	-A:A	-A:A
[A, B]	A:B	A:B
[A, B, C, D]	A:B	C:D

Workspace is used only to set plot bounds.

add(polygon)[source]

Add a polygon to map

Parameters:: polygon (Polygon2 or ndarray(2,N)) – a polygon

iscollision(polygon)[source]

Test for collision

Parameters:: polygon (Polygon2 or ndarray(2,N)) – a polygon
Returns:: collision
Return type:: bool

The polygon is tested against polygons in the map, and returns True on the first collision.

Seealso:: add() Polygon2

plot(block=None)[source]

isoccupied(p)[source]

Test if point lies inside an obstacle

Parameters:: p (array_like(2)) – a 2D point
Returns:: enclosure
Return type:: bool

The point is tested for enclosure by polygons in the map, and returns True on the first enclosure.

property workspace

Bounds of the occupancy grid

Returns:: workspace bounds [xmin, xmax, ymin, ymax]
Return type:: ndarray(4)

Returns the bounds of the occupancy grid.