vectorfield(fun, xlim, ylim, n = 16,
scale = 0.05, col = "green", ...)
Arguments
- fun
function of two variables — must be vectorized.
- xlim
range of x values.
- ylim
range of y values.
- n
grid size, proposed 16 in each direction.
- scale
scales the length of the arrows.
- col
arrow color, proposed `green'.
- ...
more options presented to the arrows primitive.
Details
Plots a vector field for a function f. Main usage could be to plot
the solution of a differential equation into the same graph.
Value
Opens a graph window and plots the vector field.
Examples
f <- function(x, y) x^2 - y^2
xx <- c(-1, 1); yy <- c(-1, 1)
if (FALSE) { # \dontrun{
vectorfield(f, xx, yy, scale = 0.1)
for (xs in seq(-1, 1, by = 0.25)) {
sol <- rk4(f, -1, 1, xs, 100)
lines(sol$x, sol$y, col="darkgreen")
}
grid()} # }