The code should look like this:

output = File("waveEqn.pvd")
output << phi
while t < T:
   ...
   t += dt
   step += 1
   if step % 10 == 0:
      output << phi

On 22 December 2015 at 12:06, Angwenyi David <kipkoej@gmail.com> wrote:
Dear Cotter,

I did so, but got a single file. I thought I could get as many files as timesteps; which files I could open all at once in Paraview to generate a video. Any direction?

Angwenyi

On 22 Dec 2015, at 12:10, Colin Cotter <colin.cotter@imperial.ac.uk> wrote:

del output