route_slope_matrix {stplanr}

Calculate the gradient of line segments from a matrix of coordinates

Description

Calculate the gradient of line segments from a matrix of coordinates

Usage

route_slope_matrix(m, e = m[, 3], lonlat = TRUE)

Arguments

m

Matrix containing coordinates and elevations

e

Elevations in same units as x (assumed to be metres)

lonlat

Are the coordinates in lon/lat order? TRUE by default

See Also

Other route_funs: route_average_gradient(), route_rolling_average(), route_rolling_diff(), route_rolling_gradient(), route_sequential_dist(), route_slope_vector()

Examples

x <- c(0, 2, 3, 4, 5, 9)
y <- c(0, 0, 0, 0, 0, 9)
z <- c(1, 2, 2, 4, 3, 1) / 10
m <- cbind(x, y, z)
plot(x, z, ylim = c(-0.5, 0.5), type = "l")
(gx <- route_slope_vector(x, z))
(gxy <- route_slope_matrix(m, lonlat = FALSE))
abline(h = 0, lty = 2)
points(x[-length(x)], gx, col = "red")
points(x[-length(x)], gxy, col = "blue")
title("Distance (in x coordinates) elevation profile",
  sub = "Points show calculated gradients of subsequent lines"
)