Add Nodes on the Circumference of an Object

Used in the overlap_with_objects function for creating nodes of which their presence within an agent can be checked in an efficient way (see moving_options and in_object). Currently works for all instances of object-class, but only returns NULL for the segment-class.

Usage

nodes_on_circumference(object, ...)

# S4 method for class 'polygon'
nodes_on_circumference(object, space_between = 0.05, cpp = FALSE)

# S4 method for class 'circle'
nodes_on_circumference(object, space_between = 0.05, cpp = FALSE)

# S4 method for class 'segment'
nodes_on_circumference(object, ...)

Arguments

object

Object of object-class.

...

Arguments passed on to the methods of this generic

space_between

Numeric denoting the space to leave between the circumference of the object and the nodes to create. When outside = TRUE, space_between distance is created to the outside of the object, while if outside = FALSE this same distance is created towards the inside of the object. Defaults to 5e-2.

cpp

Logical denoting whether to use the Rcpp alternative (TRUE) or the R alternative of this function (FALSE). Defaults to FALSE.

Value

Numerical matrix containing the nodes that were created around/within the provided object.

Details

Related to the add_nodes with the main difference being that the add_nodes adds nodes around or within an object, while nodes_on_circumference adds nodes directly on the circumference of an object.

Note that while rectangle-class is not explicitly mentioned here, this method does work for this class of objects.

See also

circle-class, polygon-class, rectangle-class, segment-class, add_nodes, in_object, moving_options

Examples

# Create an object
my_circle <- circle(center = c(0, 0), radius = 1)

# Generate nodes that fall around this circle with a distance of 1 around 
# the circle
nodes_on_circumference(my_circle, space_between = pi / 2)
#>               [,1]          [,2]
#> [1,]  1.000000e+00  0.000000e+00
#> [2,]  6.123234e-17  1.000000e+00
#> [3,] -1.000000e+00  1.224647e-16
#> [4,] -1.836970e-16 -1.000000e+00

# Note that for segments, this function returns NULL
my_segment <- segment(from = c(0, 0), to = c(2, 2))
nodes_on_circumference(my_segment)
#> NULL