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