# secant_intersections: Calculate Intersections of Circle by a Straight Line In treePlotArea: Correction Factors for Tree Plot Areas Intersected by Stand Boundaries

 secant_intersections R Documentation

## Calculate Intersections of Circle by a Straight Line

### Description

The circle is centered a (0, 0) and has radius r, the line is given in slope-intercept from.

### Usage

``````secant_intersections(a, b, r, verbose = FALSE)
``````

### Arguments

 `a` The secant's intercept. `b` The secant's slope. `r` The circle's radius `verbose` Be verbose?

### Value

A matrix of x und y values. For a tangent, both rows are identical, for a straight line missing the circle, a matrix of `NA`.

### Examples

``````secant_intersections(a = 0, b = 1, r = 2)
# A tangent
secant_intersections(a = 2, b = 0, r = 2, verbose = TRUE)
# Missing the circle
secant_intersections(a = 3, b = 0, r = 2)
# Creating a circle boundary approximation
plot(0, 0, col = "red", pch = "+",
xlim = c(-2, 2),
ylim = c(-2, 2))
for (i in seq(-1, 1, by = 0.01)) {
points(secant_intersections(Inf, i, 1), pch = "+")
}
``````

treePlotArea documentation built on June 22, 2024, 6:57 p.m.