Circle {PlaneGeometry} | R Documentation |
R6 class representing a circle
Description
A circle is given by a center and a radius,
named center
and radius
.
Active bindings
center
get or set the center
radius
get or set the radius
Methods
Public methods
Method new()
Create a new Circle
object.
Usage
Circle$new(center, radius)
Arguments
center
the center
radius
the radius
Returns
A new Circle
object.
Examples
circ <- Circle$new(c(1,1), 1) circ circ$center circ$center <- c(0,0) circ
Method print()
Show instance of a circle object.
Usage
Circle$print(...)
Arguments
...
ignored
Examples
Circle$new(c(0,0), 2)
Method pointFromAngle()
Get a point on the reference circle from its polar angle.
Usage
Circle$pointFromAngle(alpha, degrees = TRUE)
Arguments
alpha
a number, the angle
degrees
logical, whether
alpha
is given in degrees
Returns
The point on the circle with polar angle alpha
.
Method diameter()
Diameter of the reference circle for a given polar angle.
Usage
Circle$diameter(alpha)
Arguments
alpha
an angle in radians, there is one diameter for each value of
alpha
modulopi
Returns
A segment (Line
object).
Examples
circ <- Circle$new(c(1,1), 5) diams <- lapply(c(0, pi/3, 2*pi/3), circ$diameter) plot(NULL, type="n", asp=1, xlim = c(-4,6), ylim = c(-5,7), xlab = NA, ylab = NA) draw(circ, lwd = 2, col = "yellow") invisible(lapply(diams, draw, col = "blue"))
Method tangent()
Tangent of the reference circle at a given polar angle.
Usage
Circle$tangent(alpha)
Arguments
alpha
an angle in radians, there is one tangent for each value of
alpha
modulo2*pi
Examples
circ <- Circle$new(c(1,1), 5) tangents <- lapply(c(0, pi/3, 2*pi/3, pi, 4*pi/3, 5*pi/3), circ$tangent) plot(NULL, type="n", asp=1, xlim = c(-4,6), ylim = c(-5,7), xlab = NA, ylab = NA) draw(circ, lwd = 2, col = "yellow") invisible(lapply(tangents, draw, col = "blue"))
Method tangentsThroughExternalPoint()
Return the two tangents of the reference circle passing through an external point.
Usage
Circle$tangentsThroughExternalPoint(P)
Arguments
P
a point external to the reference circle
Returns
A list of two Line
objects, the two tangents; the
tangency points are in the B
field of the lines.
Method isEqual()
Check whether the reference circle equals another circle.
Usage
Circle$isEqual(circ)
Arguments
circ
a
Circle
object
Method isDifferent()
Check whether the reference circle differs from another circle.
Usage
Circle$isDifferent(circ)
Arguments
circ
a
Circle
object
Method isOrthogonal()
Check whether the reference circle is orthogonal to a given circle.
Usage
Circle$isOrthogonal(circ)
Arguments
circ
a
Circle
object
Method angle()
Angle between the reference circle and a given circle, if they intersect.
Usage
Circle$angle(circ)
Arguments
circ
a
Circle
object
Method includes()
Check whether a point belongs to the reference circle.
Usage
Circle$includes(M)
Arguments
M
a point
Method orthogonalThroughTwoPointsOnCircle()
Orthogonal circle passing through two points on the reference circle.
Usage
Circle$orthogonalThroughTwoPointsOnCircle(alpha1, alpha2, arc = FALSE)
Arguments
alpha1, alpha2
two angles defining two points on the reference circle
arc
logical, whether to return only the arc at the interior of the reference circle
Returns
A Circle
object if arc=FALSE
, an Arc
object
if arc=TRUE
, or a Line
object: the diameter
of the reference circle defined by the two points in case when the two
angles differ by pi
.
Examples
# hyperbolic triangle circ <- Circle$new(c(5,5), 3) arc1 <- circ$orthogonalThroughTwoPointsOnCircle(0, 2*pi/3, arc = TRUE) arc2 <- circ$orthogonalThroughTwoPointsOnCircle(2*pi/3, 4*pi/3, arc = TRUE) arc3 <- circ$orthogonalThroughTwoPointsOnCircle(4*pi/3, 0, arc = TRUE) opar <- par(mar = c(0,0,0,0)) plot(0, 0, type = "n", asp = 1, xlim = c(2,8), ylim = c(2,8)) draw(circ) draw(arc1, col = "red", lwd = 2) draw(arc2, col = "green", lwd = 2) draw(arc3, col = "blue", lwd = 2) par(opar)
Method orthogonalThroughTwoPointsWithinCircle()
Orthogonal circle passing through two points within the reference circle.
Usage
Circle$orthogonalThroughTwoPointsWithinCircle(P1, P2, arc = FALSE)
Arguments
P1, P2
two distinct points in the interior of the reference circle
arc
logical, whether to return the arc joining the two points instead of the circle
Returns
A Circle
object or an Arc
object,
or a Line
object if the two points are on a diameter.
Examples
circ <- Circle$new(c(0,0),3) P1 <- c(1,1); P2 <- c(1, 2) ocirc <- circ$orthogonalThroughTwoPointsWithinCircle(P1, P2) arc <- circ$orthogonalThroughTwoPointsWithinCircle(P1, P2, arc = TRUE) plot(0, 0, type = "n", asp = 1, xlab = NA, ylab = NA, xlim = c(-3, 4), ylim = c(-3, 4)) draw(circ, lwd = 2) draw(ocirc, lty = "dashed", lwd = 2) draw(arc, lwd = 3, col = "blue")
Method power()
Power of a point with respect to the reference circle.
Usage
Circle$power(M)
Arguments
M
point
Returns
A number.
Method radicalCenter()
Radical center of two circles.
Usage
Circle$radicalCenter(circ2)
Arguments
circ2
a
Circle
object
Method radicalAxis()
Radical axis of two circles.
Usage
Circle$radicalAxis(circ2)
Arguments
circ2
a
Circle
object
Returns
A Line
object.
Method rotate()
Rotate the reference circle.
Usage
Circle$rotate(alpha, O, degrees = TRUE)
Arguments
alpha
angle of rotation
O
center of rotation
degrees
logical, whether
alpha
is given in degrees
Returns
A Circle
object.
Method translate()
Translate the reference circle.
Usage
Circle$translate(v)
Arguments
v
the vector of translation
Returns
A Circle
object.
Method invert()
Invert the reference circle.
Usage
Circle$invert(inversion)
Arguments
inversion
an
Inversion
object
Returns
A Circle
object or a Line
object.
Method asEllipse()
Convert the reference circle to an Ellipse
object.
Usage
Circle$asEllipse()
Method randomPoints()
Random points on or in the reference circle.
Usage
Circle$randomPoints(n, where = "in")
Arguments
n
an integer, the desired number of points
where
"in"
to generate inside the circle,"on"
to generate on the circle
Returns
The generated points in a two columns matrix with n
rows.
Method clone()
The objects of this class are cloneable with this method.
Usage
Circle$clone(deep = FALSE)
Arguments
deep
Whether to make a deep clone.
See Also
radicalCenter
for the radical center of three circles.
Examples
## ------------------------------------------------
## Method `Circle$new`
## ------------------------------------------------
circ <- Circle$new(c(1,1), 1)
circ
circ$center
circ$center <- c(0,0)
circ
## ------------------------------------------------
## Method `Circle$print`
## ------------------------------------------------
Circle$new(c(0,0), 2)
## ------------------------------------------------
## Method `Circle$diameter`
## ------------------------------------------------
circ <- Circle$new(c(1,1), 5)
diams <- lapply(c(0, pi/3, 2*pi/3), circ$diameter)
plot(NULL, type="n", asp=1, xlim = c(-4,6), ylim = c(-5,7),
xlab = NA, ylab = NA)
draw(circ, lwd = 2, col = "yellow")
invisible(lapply(diams, draw, col = "blue"))
## ------------------------------------------------
## Method `Circle$tangent`
## ------------------------------------------------
circ <- Circle$new(c(1,1), 5)
tangents <- lapply(c(0, pi/3, 2*pi/3, pi, 4*pi/3, 5*pi/3), circ$tangent)
plot(NULL, type="n", asp=1, xlim = c(-4,6), ylim = c(-5,7),
xlab = NA, ylab = NA)
draw(circ, lwd = 2, col = "yellow")
invisible(lapply(tangents, draw, col = "blue"))
## ------------------------------------------------
## Method `Circle$orthogonalThroughTwoPointsOnCircle`
## ------------------------------------------------
# hyperbolic triangle
circ <- Circle$new(c(5,5), 3)
arc1 <- circ$orthogonalThroughTwoPointsOnCircle(0, 2*pi/3, arc = TRUE)
arc2 <- circ$orthogonalThroughTwoPointsOnCircle(2*pi/3, 4*pi/3, arc = TRUE)
arc3 <- circ$orthogonalThroughTwoPointsOnCircle(4*pi/3, 0, arc = TRUE)
opar <- par(mar = c(0,0,0,0))
plot(0, 0, type = "n", asp = 1, xlim = c(2,8), ylim = c(2,8))
draw(circ)
draw(arc1, col = "red", lwd = 2)
draw(arc2, col = "green", lwd = 2)
draw(arc3, col = "blue", lwd = 2)
par(opar)
## ------------------------------------------------
## Method `Circle$orthogonalThroughTwoPointsWithinCircle`
## ------------------------------------------------
circ <- Circle$new(c(0,0),3)
P1 <- c(1,1); P2 <- c(1, 2)
ocirc <- circ$orthogonalThroughTwoPointsWithinCircle(P1, P2)
arc <- circ$orthogonalThroughTwoPointsWithinCircle(P1, P2, arc = TRUE)
plot(0, 0, type = "n", asp = 1, xlab = NA, ylab = NA,
xlim = c(-3, 4), ylim = c(-3, 4))
draw(circ, lwd = 2)
draw(ocirc, lty = "dashed", lwd = 2)
draw(arc, lwd = 3, col = "blue")