rotate_points: Rotate points in a 2-d plane

In jsta/glatos: A package for the Great Lakes Acoustic Telemetry Observation System

Rotate points in a 2-d plane

Description

Rotate points around a point in a 2-d plane

Usage

rotate_points(x, y, theta, focus)

Arguments

x	A numeric vector of x coordinates; minimum of 2.
y	A numeric vector of y coordinates; minimum of 2.
theta	A numeric scalar with the angle of rotation in degrees; positive is clockwise.
focus	A numeric vector of x (first element) and y (second element) coordinates for the point around which x and y will rotate.

Details

Points are shifted to be centered at the focus, then rotated using a rotation matrix, then shifted back to original focus.

Value

A two-column data frame containing:

x	x coordinates
y	y coordinates

Note

This function is called from crw_in_polygon

Author(s)

C. Holbrook ([e-mail])

Examples

x <- runif(10,0,10)
y <- runif(10,0,10)
plot(x,y,type="b",pch=20)
foo <- rotate_points(x, y, 20, c(5, 5))
points(foo$x,foo$y,type="b",pch=20,col="red")

jsta/glatos documentation built on July 11, 2022, 7:01 a.m.