Getter/Setter for the points-slot

Works for all extensions of the object-class. Note that you can only change the points slot for the polygon-class and the segment-class.

Usage

points(object) <- value

# S4 method for class 'polygon'
points(x, ...)

# S4 method for class 'polygon'
points(object) <- value

# S4 method for class 'rectangle'
points(x, ...)

# S4 method for class 'circle'
points(x, length.out = 100, ...)

# S4 method for class 'segment'
points(x, ...)

# S4 method for class 'segment'
points(object) <- value

Arguments

value

Value with which to replace the original value of the points slot.

x, object

An instance of the object-class. Note that for this function x and object are synonymous: The x argument is included to ensure compatibility with the points function from base R.

...

Arguments passed on to the methods of this generic

length.out

Numeric denoting the number of points to create when the provided object is of an instance circle-class. Defaults to 100

Details

Note that for the circle-class, you can only access the points slot and not change it. This is because circles don't have a finite number of points that make up their shape, and we therefore sample points from the circumference of the circle when calling the points method.

See also

agent-class, circle-class, object-class, polygon-class, rectangle-class, segment-class

Examples

# Initialize a rectangle
my_polygon <- polygon(cbind(c(1, 1, -1, -1), 
                            c(1, -1, -1, 1)))

# Access the points slot
points(my_polygon)
#>      [,1] [,2]
#> [1,]    1    1
#> [2,]    1   -1
#> [3,]   -1   -1
#> [4,]   -1    1

# Change the points slot
points(my_polygon) <- cbind(c(2, 2, -2, -2), 
                            c(2, -2, -2, 2))
points(my_polygon)
#>      [,1] [,2]
#> [1,]    2    2
#> [2,]    2   -2
#> [3,]   -2   -2
#> [4,]   -2    2

# For circles, we can only access the points slot and provide an argument 
# denoting how many points we want to sample from the circle's 
# circumference
my_circle <- circle(center = c(0, 0), 
                    radius = 1)

points(my_circle, length.out = 10)#' 
#>            [,1]          [,2]
#>  [1,]  1.000000  0.000000e+00
#>  [2,]  0.809017  5.877853e-01
#>  [3,]  0.309017  9.510565e-01
#>  [4,] -0.309017  9.510565e-01
#>  [5,] -0.809017  5.877853e-01
#>  [6,] -1.000000  1.224647e-16
#>  [7,] -0.809017 -5.877853e-01
#>  [8,] -0.309017 -9.510565e-01
#>  [9,]  0.309017 -9.510565e-01
#> [10,]  0.809017 -5.877853e-01