# primary_scales

Characteristic values to scale each objective function

**Specification**

*Alias:*objective_function_scales*Arguments:*REALLIST*Default:*1.0 (no scaling)

**Description**

Each real value in `primary_scales`

is a nonzero characteristic value
to be used in scaling each objective function. They only have effect
when the associated method specifies `scaling`

.

This keyword is required for
`primary_scale_types`

of <tt>’value’</tt> and
optional for <tt>’log’</tt>. When specified in conjunction with log,
scale values are applied prior to the logarithm, to permit log scaling
of strictly negative response functions.

Length: When specified, `primary_scales`

must have length one of:

One (the single value will be applied to each objective function); or

Number of response groups (

`objective_functions`

), so the number of scalars plus the number of fields when fields are present; orTotal number of response elements, so the number of scalar responses plus the sum of the lengths of the fields.

*Usage Tips:*

When `primary_scales`

are specified, but not
`primary_scale_types`

, the scaling type is assumed
to be ‘value’ for all primary response functions.

Use scale values of 1.0 to selectively avoid scaling a subset of response functions.

When scaling is active, it is applied to objective functions prior to
any `weights`

and multi-objective sum
formation. See the equations in `objective_functions`

.

See the scaling information under specific methods, e.g.,
`method-*-scaling`

for details on how to use this keyword.