This is a bug, could you file an issue? Thanks! Note that some solvers, even some of the Runge-Kutta family work, for instance ode78, ode45_fe, ode21 or ode23s.
On Fri, 2016-06-24 at 20:48, Chris <7hunderstr...@gmail.com> wrote: > Hello, > > I came across this issue (recreated here using example code): > > julia> using ODE > > julia> function f(t, y) > # Extract the components of the y vector > (x, v) = y > > # Our system of differential equations > x_prime = v > v_prime = -x > > # Return the derivatives as a vector > [x_prime; v_prime] > end; > > julia> # Initial condtions -- x(0) and x'(0) > const start = [0.0; 0.1] > WARNING: redefining constant start > 2-element Array{Float64,1}: > 0.0 > 0.1 > > julia> # Time vector going from 0 to 2*PI in 0.01 increments > time = 0.:-.1:-4pi; > > julia> t, y = ode45(f, start, time); > > This hangs for a long time (I've waited up to a minute before killing it). > Is this a bug, or something I'm doing wrong? I do notice that reversing the > time vector (-4pi:.1:0.0) yields a result. > > Thanks, > Chris