The sweep algorithm is not a true optimization algorithm, but instead is simply a tool to automate a large number of analyses at distributed points in space.
Sweeps also allow you to define a discrete set of values for each variable, for all variable types (expression, choice and file), as opposed to simply a range. The range specified in the variable definition can be used as is, or overridden in the sweep setup.
You can define the following sweep types for each expression variable in the sweep setup:
Defined by Variable - use the range (min/max/increment) specified by the variable.
Linear Range Increment - override the variable's specified range with a different min, max, and increment.
Linear Range Count - override the variable's specified range with a different min, max, and count.
Custom List - allows you to use the ellipsis button in the far right column to define individual values for this variable. For expression variables you may enter the values directly into the Custom Values cell.