regarding regular spacing such as 7mm. Is there a reason to use it vs.
oct and ico?
ico and oct were added to be better than the 7mm spacing which is
there for historical
reasons. Is it the moment to drop support of regular spacings?
just throwing thoughts...

On Sat, Sep 14, 2013 at 6:43 PM, Alexandre Gramfort
<alexandre.gramfort@m4x.org> wrote:
>> To be consistent with do_forward_solution, I think we should make it so fname=None does not output a file at all, with fname=True using the MNE default name. I like having these in one function because it seems simpler to me, more consistent with do_forward_solution, and eventually less cumbersome on users (I imagine most will just create and write as opposed to doing anything with it in Python, so making this a two-step process increases work for users), but I'm okay with changing it for clarity's sake. Let me know...
>
> why do you think of
>
> ```
> def make_source_space(subject, spacing='oct6', surface='white',
> return_fname=False):
>     ...
>     if return_fname:
>          return src, fname
>     else:
>          return src
>
> def setup_source_space(subject, spacing='oct6', surface='white',
> overwrite=False):
>     src, fname = make_source_space(subject, spacing, surface, return_fname=True)
>     return None
> ```
>
> when we'll have forward modeling in memory with Python or C-bindings
> we won't need
> any more to store the source spaces. Basically I want to avoid disk usage.
> I see around me 500GB of data for a simple 20 subjects study while it
> takes 15 mins
> to recompute everything. Also I want to be able to work on my laptop
> with 500GB of disk space :)