Why does my Surface Viewer in the Fuzzy Logic Toolbox show an incorrect range of values for Sugeno systems?

Why does my Surface Viewer in the Fuzzy Logic Toolbox show an incorrect range of values for Sugeno systems?

When I plot my Surface Viewer the output range on the Z-axes is not the same as the Range specified in the membership function editor.

Answer 1

[MathWorks Support Team]

For Sugeno Sytems, the range of output is determined explicitly by the range and type of input membership functions (MF) (see, eg., SUGMAX).

Hence the surface plot of surfview is not affected by the choice of output range. For Sugeno systems, this is not a useful property because outputs are not fuzzy sets.

PLEASE NOTE: For Mamdani systems, the range of output depends upon both the input and the output MF ranges, since both inputs and outputs are fuzzy sets. The MF ranges are determined by the 'parameter' field of each MF. The range of an output should, typically, be selected such that it contains the overall min and max values of all MFs of the output.