Routine Name:   setrandfield

Description:    Sets an element field to a random value

Usage:                                  | [-uniform low high]
                setrandfield path field | [-gaussian mean sd]
                                        | [-exponential mid max] 

Example:        setrandfield /pyr/pyramidal[]/HH_Na_channel \
                    X_alpha_V0 -gaussian -40 3

Notes:          In the example above (from Scripts/piriform/pyramidal.g),
                setrandfield is being used to give some variation to the
                voltage dependence of the activation of Na channels used in
                all of the pyramidal cells used in the model.  In this case,
                there is a gaussian distribution about the mean of -40 mV,
                with a standard deviation of 3 mV.  Another use of the
                setrandfield comamnd would be to use it in script function to
                be executed as the command of a script_out object, or as the
                PROCESS action of an extended object, in order to randomly
                change a field at every time step.  This would be a way to
                inject a noise current into a compartment, for example.

                The -uniform option gives a a random number taken from a
                uniform distribution in the range "low" to "high".

                The -exponential option gives a random number taken from an
                exponential distribution with a minimum value of zero, a 1/e
                point of "mid" and a maximum value of "max".  Versions of
                GENESIS prior to 2.2 used a different interpretation of the
                two arguments.

See also:       setfield
