Exercise (Fuzzy Reasoning)
I hope you could understand the min-max method of Fuzzy reasoning, using the following Go programming list.
package main
import (
"fmt"
"os"
)
func max_2(a, b float64) float64 {
if a > b {
return a
} else {
return b
}
}
func min_2(a, b float64) float64 {
if a > b {
return b
} else {
return a
}
}
type condition_MF3 struct { // Base class for condition_MF3
center float64
width float64
express string
}
func new_condition_MF3(_center, _width float64, _express string) *condition_MF3 {
c3 := new(condition_MF3)
c3.center = _center
c3.width = _width
c3.express = _express
return c3
}
// Class for the membership function (3 mountains) of the former case
func (c3 *condition_MF3) func_X(_x float64) float64 {
// x,y denote coordinates on the membership function
x := _x
y := 0.0 // The value of y is always greater than or equal to 0 and less than or equal to 1
if c3.express == "LESS" {
if x <= c3.center-c3.width {
y = 1.0
} else if x <= c3.center {
y = -1.0 / c3.width * (x - c3.center)
} else {
y = 0.0
}
} else if c3.express == "COMMON" {
if x <= c3.center-c3.width {
y = 0.0
} else if x <= c3.center {
y = 1.0/c3.width*(x-c3.center) + 1.0
} else if x <= c3.center+c3.width {
y = -1.0/c3.width*(x-c3.center) + 1.0
} else {
y = 0.0
}
} else if c3.express == "MORE" {
if x <= c3.center {
y = 0.0
} else if x <= c3.center+c3.width {
y = 1.0 / c3.width * (x - c3.center)
} else {
y = 1.0
}
} else {
fmt.Println("MF3: wrong expression")
os.Exit(1)
}
return y
}
type condition_MF5 struct { // Base class for condition_MF5
center float64
width float64
express string
}
func new_condition_MF5(_center, _width float64, _express string) *condition_MF5 {
c5 := new(condition_MF5)
c5.center = _center
c5.width = _width
c5.express = _express
return c5
}
func (c5 *condition_MF5) func_X(_x float64) float64 {
// Class for the former membership function (5 mountains)
// x,y are the coordinates on the membership function
x := _x
y := 0.0 // The value of y is always greater than or equal to 0 and less than or equal to 1
if c5.express == "LESSLESS" {
if x <= c5.center-2.0*c5.width {
y = 1.0
} else if x <= c5.center-c5.width {
y = -1.0/c5.width*(x-(c5.center-2.0*c5.width)) + 1.0
} else {
y = 0.0
}
} else if c5.express == "LESS" {
if x <= c5.center-2.0*c5.width {
y = 0.0
} else if x <= c5.center-c5.width {
y = 1.0/c5.width*(x-(c5.center-c5.width)) + 1.0
} else if x <= c5.center {
y = -1.0/c5.width*(x-(c5.center-c5.width)) + 1.0
} else {
y = 0.0
}
} else if c5.express == "COMMON" {
if x <= c5.center-c5.width {
y = 0.0
} else if x <= c5.center {
y = 1.0/c5.width*(x-c5.center) + 1.0
} else if x <= c5.center+c5.width {
y = -1.0/c5.width*(x-c5.center) + 1.0
} else {
y = 0.0
}
} else if c5.express == "MORE" {
if x <= c5.center {
y = 0.0
} else if x <= c5.center+c5.width {
y = 1.0/c5.width*(x-(c5.center+c5.width)) + 1.0
} else if x <= c5.center+2.0*c5.width {
y = -1.0/c5.width*(x-(c5.center+c5.width)) + 1.0
} else {
y = 0.0
}
} else if c5.express == "MOREMORE" {
if x <= c5.center+c5.width {
y = 0.0
} else if x <= c5.center+2.0*c5.width {
y = 1.0/c5.width*(x-(c5.center+2.0*c5.width)) + 1.0
} else {
y = 1.0
}
} else {
fmt.Println("MF5 func_X(): wrong expression")
os.Exit(1)
}
return y
}
/////////////////////////////
type action_MF5 struct { // Base class for action_MF5
center float64
width float64
express string
x float64
y float64
}
type action_MF3 struct { // Base class for action_MF3
center float64
width float64
express string
x float64
y float64
}
func new_action_MF5(_center, _width float64, _express string) *action_MF5 {
a5 := new(action_MF5)
a5.center = _center
a5.width = _width
a5.express = _express
if a5.express == "LESSLESS" {
a5.x = a5.center - 2.0*a5.width
} else if a5.express == "LESS" {
a5.x = a5.center - a5.width
} else if a5.express == "COMMON" {
a5.x = a5.center
} else if a5.express == "MORE" {
a5.x = a5.center + a5.width
} else if a5.express == "MOREMORE" {
a5.x = a5.center + 2.0*a5.width
} else {
fmt.Println("new_action_MF5: wrong scale expression")
os.Exit(-1)
}
a5.y = 0.0
return a5
}
func new_action_MF3(_center, _width float64, _express string) *action_MF3 {
a3 := new(action_MF3)
a3.center = _center
a3.width = _width
a3.express = _express
if a3.express == "LESS" {
a3.x = a3.center - a3.width
} else if a3.express == "COMMON" {
a3.x = a3.center
} else if a3.express == "MORE" {
a3.x = a3.center + a3.width
} else {
fmt.Println("new_action_MF3: wrong scale expression")
os.Exit(-1)
}
a3.y = 0.0
return a3
}
// The latter membership function (5 mountains) class
func (a5 *action_MF5) func_Y() float64 {
return a5.y
}
// The latter membership function (3 mountains) class
func (a3 *action_MF3) func_Y() float64 {
return a3.y
}
func (a5 *action_MF5) func_Max(b float64) {
a5.y = max_2(b, a5.y)
}
func (a3 *action_MF3) func_Max(b float64) {
a3.y = max_2(b, a3.y)
}
func (a5 *action_MF5) func_X() float64 {
return a5.x
}
func (a3 *action_MF3) func_X() float64 {
return a3.x
}
func fuzzy_reasoning(temp, humi float64) float64 {
// Temperature(former)
Temp_Less := new_condition_MF3(20, 10, "LESS")
Temp_Common := new_condition_MF3(20, 10, "COMMON")
Temp_More := new_condition_MF3(20, 10, "MORE")
// Humidity(former)
Humi_Less := new_condition_MF3(50, 20, "LESS")
Humi_Common := new_condition_MF3(50, 20, "COMMON")
Humi_More := new_condition_MF3(50, 20, "MORE")
// Switch(前件部)
Switch_Less := new_action_MF3(0,1,"LESS")
Switch_Common := new_action_MF3(0,1,"COMMON")
Switch_More := new_action_MF3(0,1,"MORE")
// [Rule 01]
Rule01 := min_2(Temp_More.func_X(temp), Humi_More.func_X(humi))
Switch_Less.func_Max(Rule01) // the latters values are overwritten if the value is large enough.
fmt.Println("Rule01", Rule01)
// [Rule 02]
Rule02 := min_2(Temp_Common.func_X(temp), Humi_More.func_X(humi))
Switch_Common.func_Max(Rule02) // the latters values are overwritten if the value is large enough.
fmt.Println("Rule02", Rule02)
// [Rule 03]
Rule03 := min_2(Temp_More.func_X(temp), Humi_Common.func_X(humi))
Switch_Less.func_Max(Rule03) // the latters values are overwritten if the value is large enough.
fmt.Println("Rule03", Rule03)
// [Rule 04]
Rule04 := min_2(Temp_Less.func_X(temp), Humi_Less.func_X(humi))
Switch_More.func_Max(Rule04) // the latters values are overwritten if the value is large enough.
fmt.Println("Rule04", Rule04)
// Reasoning calculations
numerator :=
Switch_Less.func_X()*Switch_Less.func_Y() +
Switch_Common.func_X()*Switch_Common.func_Y() +
Switch_More.func_X()*Switch_More.func_Y()
denominator :=
Switch_Less.func_Y() +
Switch_Common.func_Y() +
Switch_More.func_Y()
reasoning := numerator / denominator
return reasoning
}
func main(){
fmt.Println(fuzzy_reasoning(27.0, 67.0))
}