So the first option is what I have been doing. Yes only one pvd is created. But what ends up also happening is that I get hundreds of .vtu files. Are those files necessary for pvd to work? Sorry I am not in front of my computer so I can't test any of this out yet.

Justin

On Friday, November 13, 2015, Lawrence Mitchell <lawrence.mitchell@imperial.ac.uk> wrote:

> On 13 Nov 2015, at 11:47, Justin Chang <jychang48@gmail.com> wrote:
>
> Hi all,
>
> So I am running simulations which have many time steps and normally I would save the files as .pvd via outfile << File(...). This creates a new file for each time level
>
> However, if I need to solve a large geochemistry system of equations (~20 unknowns) over 100+ time steps, I would prefer not to have 2000+ pvd files sitting my file system/laptop. Is there a way to store the solution of all time levels into a single file?

You can store multiple time steps, of the same Function, in a single pvd file:

out = File("foo.pvd")

for i in range(200):
...
out << f

If you also want to store the timestep in the file, do:

for i in range(200};
...
out << (f, t)

Where t is the current timestep.

You cannot, however, store /different/ functions in the same file. So you'll presumably need one pvd per unknown. However, this is hopefully better than one per timestep as well.

Cheers,

Lawrence