show

Display signed distance map

Since R2023a

Syntax

show(map)

show(map,frame)

show(___,Name=Value)

mapimage = show(___)

[mapimage,colorbar] = show(___)

Description

show(map) displays the occupancy grid map in the current axes, with the axes labels representing the world coordinates.

show(map,frame) displays the occupancy grid map in the current axes, with the axes labels representing the coordinates in the coordinate frame frame.

show(___,Name=Value) specifies additional options specified by one or more name-value arguments.

mapimage = show(___) returns the handle to the image object mapimage, created by show.

[mapimage,colorbar] = show(___) returns the handle to the colorbar colorbar, created by show.

Examples

Get Distance to Nearest Obstacles in Signed Distance Map

Load the exampleMaps MAT file.

load exampleMaps.mat

Create a signed distance map using the simpleMap data.

sdm = signedDistanceMap(simpleMap,InterpolationMethod="none");
show(sdm,BoundaryColor=[0 0 0],Colorbar="on");

setMapData(sdm,[7 1],zeros(5,5))
getMapData(sdm,[9 2])

ans = logical
   0

show(sdm,BoundaryColor=[0 0 0],Colorbar="on");

Find the closest boundary to the coordinate, [16.25 6.25] and calculate the distance to the nearest boundary.

coord = [16.25 6.25];
boundary = closestBoundary(sdm,coord,"world")

boundary = 
boundary(:,:,1) =

   20.5000


boundary(:,:,2) =

    6.5000

dist = distance(sdm,coord)

dist = 
4

Plot the line between the queried point and the closest obstacle cell center

hold on
plot([coord(1) boundary(:,:,1)],[coord(2) boundary(:,:,2)],"-r",Marker=".",MarkerSize=10)

Note that even though distance from the queried point appears greater than 4 when plotted, the distance function calculates the distance from the nearest cell center of the queried point.

Input Arguments

map — Signed distance map

signedDistanceMap object

Signed distance map, specified as a signedDistanceMap object.

frame — Coordinate frame

"local" | "grid"

Coordinate frame, specified as either "local" or "grid".

Name-Value Arguments

Specify optional pairs of arguments as Name1=Value1,...,NameN=ValueN, where Name is the argument name and Value is the corresponding value. Name-value arguments must appear after other arguments, but the order of the pairs does not matter.

Example: signedDistanceMap(sdm,Parent=ax)

Parent — Axes to plot the map

gca (default) | Axes object | UIAxes object

Axes to plot the map specified as either an Axes or UIAxes object. See axes or uiaxes.

Colormap — Colormap values

three-column matrix of RGB triplets

Colormap values for the pixel values in the map, specified as a three-column matrix of RGB triplets. If not provided, the current colormap of the axes is used

BoundaryColor — Occupied boundary color

RGB triplet

Occupied boundary color, specified as an RGB triplet. The occupied boundary cells use the specified color when specified.

Colorbar — Use colorbar

false or 0 (default) | true or 1

Use colorbar, specified as a logical 1 (true) or 0 (false). When true, show creates a colorbar that corresponds to the Colormap input and adds it to a hidden axis behind the current axis.

Data Types: logical

VectorField — Vector field display type

"off" (default) | "Gradient" | "ClosestBoundary"

Vector field display type, specified as one of these options:

• "off" — Show no vector field.

• "Gradient" — Show gradient field superimposed on the distance map.

• "ClosestBoundary" — Show arrows that point to the nearest occupied boundary cell.

Data Types: char | string

FastUpdate — Fast updates to existing plot

false or 0 (default) | true or 1

Fast updates to existing plot, specified as a logical 0 (false) or 1 (true). If you previously plotted your map on your figure, set to 1 for a faster update to the figure. This is useful for updating the figure in a loop for fast animations.

Output Arguments

mapimage — Map image handle

image object

Map image handle, specified as a image object.

colorbar — Colorbar handle

colorbar object

Colorbar handle, returned as a colorbar object.

Version History

Introduced in R2023a