linecirc

Find intersection of line and circle in Cartesian coordinates

Syntax

[xout,yout] = linecirc(slope,intercpt,centerx,centery,radius)

Description

[xout,yout] = linecirc(slope,intercpt,centerx,centery,radius) finds the intersection of a line with the specified slope and intercept and a circle with the specified center and radius, in Cartesian coordinates.

Examples

Find Intersection of Line and Circle

Find the intersection of the line $\mathit{y}=2\mathit{x}-1$ and a circle with its center at (3, 4) and a radius of 5.

[xout,yout] = linecirc(2,-1,3,4,5)

xout = 1×2

    4.8271    0.3729

yout = 1×2

    8.6542   -0.2542

Find Intersection of Vertical Line and Circle

Find the intersection of the line $\mathit{x}=-1$ and a circle with its center at (3, 4) and a radius of 5.

[xout,yout] = linecirc(Inf,-1,3,4,5)

xout = 1×2

    -1    -1

yout = 1×2

     7     1

Input Arguments

slope — Slope of line

numeric scalar | Inf

Slope of the line, specified as a numeric scalar or Inf. Specify Inf when the line is vertical.

intercpt — Intercept of line

numeric scalar

Intercept of the line, specified as a numeric scalar.

• When slope is a numeric scalar, this argument is the y-intercept of the line.

• When slope is Inf, this argument is the x-intercept of the line.

centerx — x-coordinate of center of circle

numeric scalar

x-coordinate of the center of the circle, specified as a numeric scalar.

centery — y-coordinate of center of circle

numeric scalar

y-coordinate of the center of the circle, specified as a numeric scalar.

radius — Radius of circle

positive scalar

Radius of the circle, specified as a positive scalar.

Output Arguments

xout — x-coordinates of intersections

two-element vector

x-coordinates of the intersections, returned as a two-element vector.

• When the line is tangent to the circle, the elements of the vector are equal.

• When the line does not intersect the circle, both elements are NaN.

yout — y-coordinates of intersections

two-element vector

y-coordinates of the intersections, returned as a two-element vector.

• When the line is tangent to the circle, the elements of the vector are equal.

• When the line does not intersect the circle, both elements are NaN.

Version History

Introduced before R2006a