Added dt parameter

[tcstewar]

For some of the backends (especially nengo_brainstorm), it is quite useful to be able to adjust dt. This adds a quick command-line option to do this.

[arvoelke]

Is there an easy way to expose this value to the Nengo model (script in the GUI)? I'm thinking something like being able to use the variable nengo_gui.settings.dt (or similar) within the model.

[tcstewar]

Is there an easy way to expose this value to the Nengo model (script in the GUI)? I'm thinking something like being able to use the variable nengo_gui.settings.dt (or similar) within the model.

Currently we don't have anything like that. I could definitely see working towards that sort of direction, along with the nengo_gui.hooks discussion and also I think even how the keyboard state is kept in #942

[arvoelke]

In the mean time, here's a really hacky way to access the page settings from the file scope of the model, just in case anyone is dying for a temporary solution:

import inspect
dt = inspect.getargvalues(inspect.stack()[1][0]).locals['self'].settings.dt

(Tested with Python 2.7 and this branch of nengo-gui.)

You can also replace dt with backend to get the current backend.

Another solution could be to extend the code_locals dictionary passed into exec in some way.