Octave Fuzzy Logic Toolkit: addvar

### Function Reference: `addvar`

Function File: fis = addvar (fis, in_or_out, var_name, var_range)

Add an input or output variable to an existing FIS structure and return the updated FIS.

The types/values of the arguments are expected to be:

Argument | Expected Type or Value
--- | ---
fis | an FIS structure
in_or_out | either ’input’ or ’output’ (case-insensitive)
var_name | a string
var_range | a vector [x1 x2] of two real numbers

The vector components x1 and x2, which must also satisfy x1 <= x2, specify the lower and upper bounds of the variable’s domain.

To run the demonstration code, type "`demo addvar`" (without the quotation marks) at the Octave prompt.

### Example: 1

     a = newfis ('Heart-Disease-Risk', 'sugeno', ...
                 'min', 'max', 'min', 'max', 'wtaver');
     a = addvar (a, 'input', 'LDL-Level', [0 300]);
     getfis (a, 'input', 1);

    Name = LDL-Level
    NumMFs = 0
    MFLabels =
    Range = [0 300]