Fuzzy Logic Toolbox™

sffis - Fuzzy inference S-function for Simulink^® software

Syntax

output = sffis(t,x,u,flag,fismat) 

Description

In most cases, the Fuzzy Logic Controller block generates a custom block diagram for your FIS. The Fuzzy Wizard, however, cannot handle FIS with custom membership functions or with AND, OR, IMP, and AGG functions outside of the following list:

• orMethod:max

• andMethod: min,prod

• impMethod: min,prod

• aggMethod: max

In these cases, the Fuzzy Logic Controller block uses the S-function sffis to simulate the FIS. For more discussion of this topic, see Building Your Own Fuzzy Simulink^® Models.

The MEX-file sffis is used by Simulink to undertake the calculation normally performed by evalfis. It has been optimized to work in the Simulink environment. sffis builds a data structure in memory during the initialization phase of a Simulink simulation, which it then continues to use until the simulation is complete.

The arguments t, x, and flag are standard Simulink S-function arguments (see Writing S-Functions in the Simulink documentation). The argument u is the input to the MATLAB^® workspace FIS structure, fismat. If, for example, there are two inputs to fismat, then u is a two-element vector.

See Also

evalfis, fuzblock

setfis

showfis