# linecirc

Find intersection of line and circle in Cartesian coordinates

## Syntax

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

## Description

example

````[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

collapse all

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 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

collapse all

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

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.

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

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

Radius of the circle, specified as a positive scalar.

## Output Arguments

collapse all

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`.

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