Determines the heading between spatial points.

heading(from, to)

# S4 method for SpatialPoints,SpatialPoints
heading(from, to)

# S4 method for matrix,matrix
heading(from, to)

# S4 method for matrix,SpatialPoints
heading(from, to)

# S4 method for SpatialPoints,matrix
heading(from, to)

Arguments

from

The starting position; an object of class SpatialPoints.

to

The ending position; an object of class SpatialPoints.

Value

The heading between the points, in degrees.

Author

Eliot McIntire

Examples

library(sp)
N <- 10L                # number of agents
x1 <- stats::runif(N, -50, 50) # previous X location
y1 <- stats::runif(N, -50, 50) # previous Y location
x0 <- stats::rnorm(N, x1, 5)   # current X location
y0 <- stats::rnorm(N, y1, 5)   # current Y location

# using SpatialPoints
prev <- SpatialPoints(cbind(x = x1, y = y1))
curr <- SpatialPoints(cbind(x = x0, y = y0))
heading(prev, curr)
#>  [1]  15.787641  77.638872 105.303395 290.088318 299.359140 145.182989
#>  [7] 354.502373 263.513987  51.258376   5.642971

# using matrix
prev <- matrix(c(x1, y1), ncol = 2, dimnames = list(NULL, c("x","y")))
curr <- matrix(c(x0, y0), ncol = 2, dimnames = list(NULL, c("x","y")))
heading(prev, curr)
#>  [1]  15.787641  77.638872 105.303395 290.088318 299.359140 145.182989
#>  [7] 354.502373 263.513987  51.258376   5.642971

#using both
prev <- SpatialPoints(cbind(x = x1, y = y1))
curr <- matrix(c(x0, y0), ncol = 2, dimnames = list(NULL, c("x","y")))
heading(prev, curr)
#>  [1]  15.787641  77.638872 105.303395 290.088318 299.359140 145.182989
#>  [7] 354.502373 263.513987  51.258376   5.642971

prev <- matrix(c(x1, y1), ncol = 2, dimnames = list(NULL, c("x","y")))
curr <- SpatialPoints(cbind(x = x0, y = y0))
heading(prev, curr)
#>  [1]  15.787641  77.638872 105.303395 290.088318 299.359140 145.182989
#>  [7] 354.502373 263.513987  51.258376   5.642971