API for the qFIS Fuzzy Inference System Engine. More...

Data Structures
struct	qFIS_Input_t
	A FIS Input object. More...

struct	qFIS_Output_t
	A FIS Output object. More...

struct	qFIS_MF_t
	A FIS Membership Function. More...

struct	qFIS_t
	A FIS(Fuzzy Inference System) object. More...

Macros
#define	FIS_RULE_ITEM_SIZE

#define	FIS_RULES_MIN_VALUE

#define	QFIS_RULES_BEGIN
	Start a Fuzzy rule set. The QFIS_RULES_BEGIN statement is used to declare the starting point of a FIS rule set. It should be placed at the start of the rules enumeration. QFIS_RULES_END declare the end of the FIS rule set.

#define	QFIS_RULES_END
	Ends a Fuzzy rule set. The QFIS_RULES_END statement is used to finalize the declaration of a FIS rule set. It should be placed at the end of the rules enumeration. QFIS_RULES_BEGIN declare the start point of the FIS rule set.

#define	IF
	Rule statement to begin a rule sentence.

#define	AND
	Rule statement to represent the AND connector.

#define	OR
	Rule statement to represent the OR connector.

#define	THEN
	Rule statement to represent the implication.

#define	IS
	Rule statement to represent a premise.

#define	IS_NOT
	Rule statement to represent a negated premise.

#define	END
	Rule statement to end a rule sentence.

Typedefs
typedef int16_t	qFIS_Rules_t
	Type definition to instantiate a set of fuzzy rules.

Enumerations
enum	qFIS_MF_Name_t { custommf , trimf , trapmf , gbellmf , gaussmf , gauss2mf , sigmf , dsigmf , psigmf , pimf , smf , zmf , singletonmf , concavemf , spikemf , linsmf , linzmf , rectmf , cosmf , constantmf , linearmf , tlinsmf , tlinzmf , tconcavemf , tsigmf , tsmf , tzmf }
	An enum with all the possible values to specify a membership function. More...

enum	qFIS_DeFuzz_Method_t { centroid , bisector , mom , lom , som , wtaver , wtsum }
	An enum with all the possible de-Fuzzyfication methods. More...

enum	qFIS_ParamValue_t { qFIS_MIN , qFIS_PROD , qFIS_MAX , qFIS_PROBOR , qFIS_SUM }
	An enum with the supported parameter values. More...

enum	qFIS_Parameter_t { qFIS_Implication , qFIS_Aggregation , qFIS_AND , qFIS_OR , qFIS_EvalPoints }
	An enum with the allowed parameters that can be set on a FIS instance. More...

enum	qFIS_Type_t { Mamdani , Sugeno , Tsukamoto }
	An enum with the inference system types supported by qFIS. More...

Functions
int	qFIS_SetParameter (qFIS_t *const f, const qFIS_Parameter_t p, const qFIS_ParamValue_t x)
	Set parameters of the FIS instance.

int	qFIS_SetDeFuzzMethod (qFIS_t *const f, qFIS_DeFuzz_Method_t m)
	Change the default de-Fuzzification method of the FIS instance.

int	qFIS_Setup (qFIS_t const f, const qFIS_Type_t t, qFIS_Input_t const inputs, const size_t ni, qFIS_Output_t const outputs, const size_t no, qFIS_MF_t const mf_inputs, const size_t nmi, qFIS_MF_t const mf_outputs, const size_t nmo, const qFIS_Rules_t const r, float *wi, const size_t n)
	Setup and initialize the FIS instance.

int	qFIS_InputSetup (qFIS_Input_t *const v, const qFIS_Tag_t t, const float min, const float max)
	Setup the input with the specified tag and set limits for it.

int	qFIS_OutputSetup (qFIS_Output_t *const v, const qFIS_Tag_t t, const float min, const float max)
	Setup the output with the specified tag and set limits for it.

int	qFIS_SetInput (qFIS_Input_t *const v, const qFIS_Tag_t t, const float value)
	Set a crisp value of the input with the specified tag.

float	qFIS_GetOutput (const qFIS_Output_t *const v, const qFIS_Tag_t t)
	Get the de-fuzzified crisp value from the the output with the specified tag.

int	qFIS_SetMF (qFIS_MF_t const m, const qFIS_Tag_t io, const qFIS_Tag_t mf, const qFIS_MF_Name_t s, qFIS_MF_Fcn_t custom_mf, const float cp, const float h)
	Set the IO tag and points for the specified membership function.

int	qFIS_StoreAggregatedRegion (qFIS_Output_t const o, const qFIS_Tag_t t, float x, float *y, const size_t n)
	Set location to store the aggregated region for supplied FIS output.

int	qFIS_Fuzzify (qFIS_t *const f)
	Perform the fuzzification operation over the crisp inputs on the requested FIS object.

int	qFIS_Inference (qFIS_t *const f)
	Perform the inference process on the requested FIS object.

int	qFIS_DeFuzzify (qFIS_t *const f)
	Perform the de-Fuzzification operation to compute the crisp outputs.

int	qFIS_SetRuleWeights (qFIS_t const f, float rWeights)
	Set weights to the rules of the inference system.

Detailed Description

API for the qFIS Fuzzy Inference System Engine.

For a brief description of this module, please read Fuzzy Inference System Engine

Macro Definition Documentation

◆ QFIS_RULES_BEGIN

#define QFIS_RULES_BEGIN

Start a Fuzzy rule set. The QFIS_RULES_BEGIN statement is used to declare the starting point of a FIS rule set. It should be placed at the start of the rules enumeration. QFIS_RULES_END declare the end of the FIS rule set.

See also: QFIS_RULES_END

Warning: Only one segment is allowed inside a fuzzy rule set.

Note: It must always be used together with a matching QFIS_RULES_END statement. Example:
static const qFIS_Rules_t rules[] = {

QFIS_RULES_BEGIN

QFIS_RULES_END

};

qFIS_Rules_t
int16_t qFIS_Rules_t
Type definition to instantiate a set of fuzzy rules.
Definition qfis.h:219

QFIS_RULES_END
#define QFIS_RULES_END
Ends a Fuzzy rule set. The QFIS_RULES_END statement is used to finalize the declaration of a FIS rule...
Definition qfis.h:315

QFIS_RULES_BEGIN
#define QFIS_RULES_BEGIN
Start a Fuzzy rule set. The QFIS_RULES_BEGIN statement is used to declare the starting point of a FIS...
Definition qfis.h:295

◆ QFIS_RULES_END

#define QFIS_RULES_END

Ends a Fuzzy rule set. The QFIS_RULES_END statement is used to finalize the declaration of a FIS rule set. It should be placed at the end of the rules enumeration. QFIS_RULES_BEGIN declare the start point of the FIS rule set.

See also: QFIS_RULES_BEGIN

Warning: Only one segment is allowed inside a fuzzy rule set.

Note: It must always be used together with a matching QFIS_RULES_BEGIN statement. Example:
static const qFIS_Rules_t rules[] = {

QFIS_RULES_BEGIN

QFIS_RULES_END

};

Typedef Documentation

◆ qFIS_Rules_t

typedef int16_t qFIS_Rules_t

Type definition to instantiate a set of fuzzy rules.

Rules are defined by combining I/O and membership function tags with the following statements:

QFIS_RULES_BEGIN, IF, IS, IS_NOT, AND, OR, THEN, END and QFIS_RULES_END

Example:

static const qFIS_Rules_t rules[] = {
    QFIS_RULES_BEGIN
        IF service IS service_poor OR food IS food_rancid THEN tip IS tip_cheap END
        IF service IS service_good THEN tip IS tip_average END
        IF service IS service_excellent OR food IS food_delicious THEN tip IS tip_generous END
    QFIS_RULES_END
};

Enumeration Type Documentation

◆ qFIS_DeFuzz_Method_t

enum qFIS_DeFuzz_Method_t

An enum with all the possible de-Fuzzyfication methods.

Enumerator
centroid	Center of gravity of the fuzzy set along the x-axis [ Only for Mamdani FIS ]
bisector	Vertical line that divides the fuzzy set into two sub-regions of equal area [ Only for Mamdani FIS ]
mom	Middle of Maximum [ Only for Mamdani FIS ]
lom	Largest of Maximum [ Only for Mamdani FIS ]
som	Smallest of Maximum [ Only for Mamdani FIS ]
wtaver	Weighted average of all rule outputs [ Only for Sugeno and Tsukamoto FIS ]
wtsum	Weighted sum of all rule outputs [ Only for Sugeno FIS ]

◆ qFIS_MF_Name_t

enum qFIS_MF_Name_t

An enum with all the possible values to specify a membership function.

Enumerator
custommf	Custom user-defined Membership function
trimf	Triangular Membership function f(a,b,c)
trapmf	Trapezoidal Membership function f(a,b,c,d)
gbellmf	Generalized bell-shaped Membership function f(a,b,c)
gaussmf	Gaussian Membership function f(s,c)
gauss2mf	Gaussian combination Membership function f(s1,c1,s2,c2)
sigmf	Sigmoidal Membership function f(a,c)
dsigmf	Difference between two sigmoidal Membership functions f(a1,c1,a2,c2)
psigmf	Product of two sigmoidal membership functions f(a1,c1,a2,c2)
pimf	Pi-shaped membership function f(a,b,c,d)
smf	S-shaped membership function f(a,b)
zmf	Z-shaped membership function f(a,b)
singletonmf	Singleton Membership Function f(a)
concavemf	Concave Membership Function f(i,e)
spikemf	Spike Membership Function f(w,c)
linsmf	Linear s-shaped saturation membership function f(a,b)
linzmf	Linear z-shaped saturation membership function f(a,b)
rectmf	Rectangle Membership Function f(s,e)
cosmf	Cosine Membership Function f(c,w)
constantmf	Constant membership function f(a) [Only for Sugeno FIS ]
linearmf	Linear membership function f(...) [Only for Sugeno FIS ]
tlinsmf	Tsukamoto s-shaped saturation membership function f(a,b) [Only for Tsukamoto FIS ]
tlinzmf	Tsukamoto linzmf membership function f(a,b) [ Only for Tsukamoto FIS ]
tconcavemf	Tsukamoto z-shaped saturation membership function f(i,e) [Only for Tsukamoto FIS ]
tsigmf	Tsukamoto Sigmoid membership function f(a,c) [ Only for Tsukamoto FIS ]
tsmf	Tsukamoto S-Shape membership function f(a,b) [ Only for Tsukamoto FIS ]
tzmf	Tsukamoto Z-Shape membership function f(a,b) [ Only for Tsukamoto FIS ]

◆ qFIS_Parameter_t

enum qFIS_Parameter_t

An enum with the allowed parameters that can be set on a FIS instance.

Enumerator
qFIS_Implication	Only qFIS_MIN and qFIS_PROD supported
qFIS_Aggregation	Only qFIS_MAX, qFIS_PROBOR and qFIS_SUM supported
qFIS_AND	Only qFIS_MIN and qFIS_PROD supported
qFIS_OR	Only qFIS_MAX and qFIS_PROBOR supported
qFIS_EvalPoints	The number of points for de-fuzzification

◆ qFIS_ParamValue_t

enum qFIS_ParamValue_t

An enum with the supported parameter values.

Enumerator
qFIS_MIN	Minimal value
qFIS_PROD	Product
qFIS_MAX	Maximum value
qFIS_PROBOR	Probabilistic OR
qFIS_SUM	Sum

◆ qFIS_Type_t

enum qFIS_Type_t

An enum with the inference system types supported by qFIS.

Enumerator
Mamdani	Mamdani inference system. The output of each rule its a fuzzy logic set.
Sugeno	Takagi-Sugeno inference system. The output of each rule its a function either linear or constant.
Tsukamoto	Mamdani inference system. The output of each rule its a fuzzy logic set represented with a monotonic membership function.

Function Documentation

◆ qFIS_DeFuzzify()

int qFIS_DeFuzzify ( qFIS_t *const f )

Perform the de-Fuzzification operation to compute the crisp outputs.

Precondition: The instance should have already invoked the inference process successfully with qFIS_Inference()

Note: By default, this function, this API uses the Centroid method on Mamdani type FIS and weight-average on Sugeno type FIS. To change the default settings use the qFIS_SetDeFuzzMethod() function.

Parameters

[in] f A pointer to the Fuzzy Inference System instance.

Returns: 1 on success, otherwise return 0.

◆ qFIS_Fuzzify()

int qFIS_Fuzzify ( qFIS_t *const f )

Perform the fuzzification operation over the crisp inputs on the requested FIS object.

Precondition: I/Os and fuzzy sets must be previously initialized by qFIS_InputSetup(), qFIS_OutputSetup(), qFIS_SetMF() and qFIS_Setup() respectively.

Parameters

[in] f A pointer to the Fuzzy Inference System instance.

Returns: 1 on success, otherwise return 0.

◆ qFIS_GetOutput()

float qFIS_GetOutput	(	const qFIS_Output_t *const	v,
		const qFIS_Tag_t	t )

Get the de-fuzzified crisp value from the the output with the specified tag.

Parameters

[in]	v	An array with the FIS inputs as a qFIS_Output_t array.
[in]	t	The output tag

Returns: The requested de-fuzzified crips value.

◆ qFIS_Inference()

int qFIS_Inference ( qFIS_t *const f )

Perform the inference process on the requested FIS object.

Precondition: The instance should have already invoked the fuzzification operation successfully with qFIS_Fuzzify()

Parameters

[in] f A pointer to the Fuzzy Inference System instance.

Returns: 1 on success, otherwise return 0.

◆ qFIS_InputSetup()

int qFIS_InputSetup	(	qFIS_Input_t *const	v,
		const qFIS_Tag_t	t,
		const float	min,
		const float	max )

Setup the input with the specified tag and set limits for it.

Parameters

[in]	v	An array with the FIS inputs as a qFIS_Input_t array.
[in]	t	The input tag
[in]	min	Minimum allowed value for this input
[in]	max	Max allowed value for this input

Returns: 1 on success, otherwise return 0.

◆ qFIS_OutputSetup()

int qFIS_OutputSetup	(	qFIS_Output_t *const	v,
		const qFIS_Tag_t	t,
		const float	min,
		const float	max )

Setup the output with the specified tag and set limits for it.

Note: limits do not apply in Sugeno outputs

Parameters

[in]	v	An array with the FIS outputs as a qFIS_Output_t array.
[in]	t	The output tag
[in]	min	Minimum allowed value for this output
[in]	max	Max allowed value for this output

Returns: 1 on success, otherwise return 0.

◆ qFIS_SetDeFuzzMethod()

int qFIS_SetDeFuzzMethod	(	qFIS_t *const	f,
		qFIS_DeFuzz_Method_t	m )

Change the default de-Fuzzification method of the FIS instance.

Parameters

[in]	f	A pointer to the Fuzzy Inference System instance.
[in]	m	The de-fuzzification method: use one of the following : centroid, bisector, mom, lom, som, wtaver, wtsum

Note: centroid, bisector, mom, lom and som only apply for a Mamdani FIS; wtaver and wtsum only apply for a Sugeno FIS.; wtaver only apply for a Tsukamoto FIS

Returns: 1 on success, otherwise return 0.

◆ qFIS_SetInput()

int qFIS_SetInput	(	qFIS_Input_t *const	v,
		const qFIS_Tag_t	t,
		const float	value )

Set a crisp value of the input with the specified tag.

Parameters

[in]	v	An array with the FIS inputs as a qFIS_Input_t array.
[in]	t	The input tag
[in]	value	The crisp value to set

Returns: 1 on success, otherwise return 0.

◆ qFIS_SetMF()

int qFIS_SetMF	(	qFIS_MF_t *const	m,
		const qFIS_Tag_t	io,
		const qFIS_Tag_t	mf,
		const qFIS_MF_Name_t	s,
		qFIS_MF_Fcn_t	custom_mf,
		const float *	cp,
		const float	h )

Set the IO tag and points for the specified membership function.

Parameters

[in]	m	An array with the required membership functions as qFIS_MF_t objects.
[in]	io	The I/O tag related with this membership function
[in]	mf	The user-defined tag for this membership function
[in]	s	The wanted shape/form for this membership function, can be one of the following: trimf, trapmf, gbellmf, gaussmf, gauss2mf, sigmf, dsigmf, psigmf, pimf, smf, zmf, singletonmf, concavemf, spikemf, linsmf, linzmf, rectmf, cosmf.

Note: For Sugeno FIS, an output membership function should be one of the following: constantmf, linearmf.; For Tsukamoto FIS, an output membership function should be one the following monotonic functions : tlinsmf, tlinzmf, tsmf, tzmf, tconcavemf; To set a custom user-defined membership function, set this argument as custommf and pass a pointer to the desired function on the custom_mf argument.

Parameters

[in]	custom_mf	Custom user-defined membership function. To ignore pass `NULL` as argument.
[in]	cp	Points or coefficients of the membership function.
[in]	h	Height of the membership function.

Note: Height parameter h does not apply for output membership functions on Sugeno and Tsukamoto inference systems. [ 0 <= h <= 1]

Returns: 1 on success, otherwise return 0.

◆ qFIS_SetParameter()

int qFIS_SetParameter	(	qFIS_t *const	f,
		const qFIS_Parameter_t	p,
		const qFIS_ParamValue_t	x )

Set parameters of the FIS instance.

Parameters

[in]	f	A pointer to the Fuzzy Inference System instance.
[in]	p	The requested parameter to change/set.
[in]	x	The value of the parameter to set.

Returns: 1 on success, otherwise return 0.

◆ qFIS_SetRuleWeights()

int qFIS_SetRuleWeights	(	qFIS_t *const	f,
		float *	rWeights )

Set weights to the rules of the inference system.

Precondition: I/Os and fuzzy sets must be previously initialized by qFIS_InputSetup(), qFIS_OutputSetup(), qFIS_SetMF() and qFIS_Setup() respectively.

Parameters

[in]	f	A pointer to the Fuzzy Inference System instance.
[in]	rWeights	An array with the values of every rule weight;

Returns: 1 on success, otherwise return 0.

◆ qFIS_Setup()

int qFIS_Setup	(	qFIS_t *const	f,
		const qFIS_Type_t	t,
		qFIS_Input_t *const	inputs,
		const size_t	ni,
		qFIS_Output_t *const	outputs,
		const size_t	no,
		qFIS_MF_t *const	mf_inputs,
		const size_t	nmi,
		qFIS_MF_t *const	mf_outputs,
		const size_t	nmo,
		const qFIS_Rules_t *const	r,
		float *	wi,
		const size_t	n )

Setup and initialize the FIS instance.

Note: Default configuration : AND = Min, OR = Max, Implication = Min Aggregation = Max, EvalPoints = 100

Parameters

[in]	f	A pointer to the Fuzzy Inference System instance.
[in]	t	Type of inference Mamdani, Sugeno or Tsukamoto.
[in]	inputs	An array with all the system inputs as qFIS_Input_t objects.
[in]	ni	The number of bytes used by inputs. Use the sizeof operator.
[in]	outputs	An array with all the system outputs as qFIS_Output_t objects.
[in]	no	The number of bytes used by outputs. Use the sizeof operator.
[in]	mf_inputs	An array with all the membership functions related to the inputs. This should be an array of qFIS_MF_t objects.
[in]	nmi	The number of bytes used by mf_inputs. Use the sizeof operator.
[in]	mf_outputs	An array with all the membership functions related to the outputs. This should be an array of qFIS_MF_t objects.
[in]	nmo	The number of bytes used by mf_outputs. Use the sizeof operator.
[in]	r	The rules set.
[in]	wi	An array of size n were the rule strengths will be stored.
[in]	n	Number of rules

Returns: 1 on success, otherwise return 0.

◆ qFIS_StoreAggregatedRegion()

int qFIS_StoreAggregatedRegion	(	qFIS_Output_t *const	o,
		const qFIS_Tag_t	t,
		float *	x,
		float *	y,
		const size_t	n )

Set location to store the aggregated region for supplied FIS output.

Note: This feature only applies to Mamdani systems.

Warning: Array size of x and y should be greater or equal to the number of evaluation points of the FIS instance.

Precondition: The FIS instance and the output should be previously configured initialized with qFIS_Setup() and qFIS_OutputSetup() respectively.

Parameters

[in]	o	An array of type qFIS_Output_t with the FIS outputs.
[in]	t	The output tag
[in]	x	Array where the x-axis points of the aggregated output will be stored
[in]	y	Array where the y-axis points of the aggregated output will be stored
[in]	n	Number of elements in x or y.

Returns: 1 on success, otherwise return 0.

Data Structures

Macros

Typedefs

Enumerations

Functions

Detailed Description

Macro Definition Documentation

◆ QFIS_RULES_BEGIN

◆ QFIS_RULES_END

Typedef Documentation

◆ qFIS_Rules_t

Enumeration Type Documentation

◆ qFIS_DeFuzz_Method_t

◆ qFIS_MF_Name_t

◆ qFIS_Parameter_t

◆ qFIS_ParamValue_t

◆ qFIS_Type_t

Function Documentation

◆ qFIS_DeFuzzify()

◆ qFIS_Fuzzify()

◆ qFIS_GetOutput()

◆ qFIS_Inference()

◆ qFIS_InputSetup()

◆ qFIS_OutputSetup()

◆ qFIS_SetDeFuzzMethod()

◆ qFIS_SetInput()

◆ qFIS_SetMF()

◆ qFIS_SetParameter()

◆ qFIS_SetRuleWeights()

◆ qFIS_Setup()

◆ qFIS_StoreAggregatedRegion()