**noiseType - sets a group's noise parameters
**
### USAGE

noiseType <group-list> [-range <range> | -multiply | -flat]

### DESCRIPTION

This command sets the type of noise function and range of the
distribution used by all of the input, output, or link derivative noise
procedures in the groups. A group can only have a single noise function
and range, as it is assumed that no more than one of these forms of
noise will be used at any one time. The actual noise procedures are
activated by including one of the following group types: DERIV_NOISE,
IN_NOISE, IN_DERIV_NOISE, OUT_NOISE, OUT_DERIV_NOISE.

The default *range* is 0.1 and the default noise procedure is
additive and gaussian. In this case the range is the standard deviation
and the
distribution is centered on 0.0. `-multiply`

will make the
noise procedure multiplicative, scaling the values based on a
distribution centered around 1.0. `-flat`

will make the
distribution uniform, rather than gaussian, where the range is half the
distribution width.

Using * in place of the group name will affect all groups.

### EXAMPLES

To use additive noise selected uniformly from the range [-0.01, +0.01)
on the "hidden" group:

lens> noise hidden -flat -r 0.01

To use multiplicative noise sampled from a gaussian distribution with
standard deviation 0.1 centered around 1.0:

lens> noise hidden -r 0.1 -m

To eliminate the effect of noise in the network:

lens> noise * -r 0

### SEE ALSO

lesionLinks,
lesionUnits,
train

Last modified: Sun Feb 28 21:37:34 EST 1999