New units

[Gannier]

hi all,

is there a way to create new units?
I want to simulate the force developed by a contractile cell with the force in Newton but this unit doesn't exist in Neuron and I don't see how to create it.

[ted]

is there a way to create new units?

Yes, but that is seldom necessary.

I want to simulate the force developed by a contractile cell with the force in Newton but this unit doesn't exist in Neuron

That would be surprising. Have you tried (newton) or (N)? NMODL's units definitions are based on the list used by the UNIX/Linux units command. Before deciding you have to define new units, take a moment to discover if what you need already exists. Please read the item
Q: What units does NEURON use for current, concentration, etc.?
in the FAQ list
http://www.neuron.yale.edu/neuron/faq/general-questions
where you will find a link to version 1.44 of units.dat, the database of units definitions that has been used by most modern UNIX/Linux distributions since April, 2005.

Note: units -V
will print a message that includes the location of the units.dat file (usually it's in /usr/share)

[Gannier]

Hi ted,

Thanks for the link to units.dat you provide, very interesting.
I tried Newton but no newton nor N. After the first try, I'm thinking that Neuron was for neuron and doesn't need to simulate force.
I'm very impressed to find force, stress and even magnetic units...

[ted]

If I declare
fx (newton)
fy (N)
in the ASSIGNED block of a mod file, modlunit is perfectly happy with that. So NMODL knows about these units.