FUZZEKS [to Index]
Membership function window: Types of membership functions
To select a membership function (theoretical details in the
overview of membership function window, you can follow the following steps:
- 1. Choose a suitable form of the membership function.
- Two possible types of function are rising:
- 'Standard rise' goes from the middle in the same manner down to
the membership value 0 at the left as it goes up to the membership
value 1 at the right (point-symmetrical).
- 'Burrough rise' goes in a similar manner up to the membership
value 1 at the right, but it never reaches the membership value 0
at the left, but it converges to 0.
- Two possible types of function are falling:
- 'Standard fall' is the horizontally mirrored version of
- 'Burrough fall' is the horizontally mirrored version of
- Two possible types of function have a peak:
- 'Standard peak' is built of 'Standard rise' on the left side,
and of 'Standard fall' on the right.
- 'Burrough peak' is built of 'Burrough rise' on the left side,
and of 'Burrough fall' on the right.
- How to operate a Windows 3.1 listbox:
To select the chosen function form, you push the button with
the small down-arrow with the help of the mouse. Then a list of
the possible forms pops up, in which you can simply click with
the mouse at the desired item.)
- 2. Enter the parameters for the chosen type of function.
- Every one of the rise or fall versions has 2 parameters. A peak
function has 4, because they consist of two rise or fall versions.
The parameters are entered in the small edit fields just below
the large rectangle in which the function will be displayed.
These edit fields have lines that are connected with the x-axis of the
function display rectangle at the x-value that is in the edit field.
- 'Standard rise', the two parameters are first the x-value
where the function begins to rise and second the x-value
where the functions value becomes 1.
- 'Burrough rise', the two parameters are the x-value, where
the function has the value 0.5 and the x-value, where the
functions value becomes 1.
The other types have similar parameters.
How to operate Windows 3.1 edit fields:
In order to fill out one of the edit fields, simply click with the
mouse into it. Then you can enter and edit the number.
You need not close the window in order to make FUZZEKS
(re)calculate all these items that are influenced by this setting.
If you enter something meaningless (such as in the left field 2 and
in the right 1), the message "Data inconsistent!" appears in
the rectangle that normally displays the function graph.