Reducers may apply weights to various inputs, average multiple estimates, merge redundant readings, and so on. Select and output the best of multiple inputs according to certain rules or criteria. Weight and combine multiple inputs based on their Accuracy and Quality . Accept a series of inputs representing values observed over time, and smooth them, average out transient noise, etc., to generate a single best current estimate. Transform two main inputs to a single value representing differences between them.
Sequential versions detect rates of changes of inputs.
Scale or transform Units or types of representation. Converters are required in cases where the same information is represented in multiple formats. For example, there are many ways of representing Earth Geometry, and clever algorithms best suited to each. Even the simple notion of Position can be represented in many ways, relative to different coordinate systems, so values must ultimately pass through converters when unified with other representations. One filter may further coordinate the effects of others by sequentially connecting the outputs of one or more function as inputs of others.