libqalculate-0.9.11
Public Member Functions | Protected Attributes | List of all members
UserFunction Class Reference

A user defined mathematical function. More...

#include <Function.h>

Inheritance diagram for UserFunction:
MathFunction ExpressionItem

Public Member Functions

 UserFunction (string cat_, string name_, string formula_, bool is_local=true, int argc_=-1, string title_="", string descr_="", int max_argc_=0, bool is_active=true)
 
 UserFunction (const UserFunction *function)
 
void set (const ExpressionItem *item)
 
ExpressionItemcopy () const
 
string formula () const
 
string internalFormula () const
 
int calculate (MathStructure &mstruct, const MathStructure &vargs, const EvaluationOptions &eo)
 
void setFormula (string new_formula, int argc_=-1, int max_argc_=0)
 
void addSubfunction (string subfunction, bool precalculate=true)
 
void setSubfunction (size_t index, string subfunction)
 
void delSubfunction (size_t index)
 
void clearSubfunctions ()
 
size_t countSubfunctions () const
 
void setSubfunctionPrecalculated (size_t index, bool precalculate)
 
const string & getSubfunction (size_t index) const
 
bool subfunctionPrecalculated (size_t index) const
 
int subtype () const
 
- Public Member Functions inherited from MathFunction
 MathFunction (string name_, int argc_, int max_argc_=0, string cat_="", string title_="", string descr_="", bool is_active=true)
 
 MathFunction (const MathFunction *function)
 
virtual int type () const
 
bool testArgumentCount (int itmp)
 
virtual MathStructure calculate (const string &eq, const EvaluationOptions &eo=default_evaluation_options)
 
virtual MathStructure parse (const string &eq, const ParseOptions &po=default_parse_options)
 
virtual int parse (MathStructure &mstruct, const string &eq, const ParseOptions &po=default_parse_options)
 
virtual MathStructure calculate (MathStructure &vargs, const EvaluationOptions &eo=default_evaluation_options)
 
string condition () const
 
string printCondition ()
 
void setCondition (string expression)
 
bool testCondition (const MathStructure &vargs)
 
int args () const
 
int minargs () const
 
int maxargs () const
 
int args (const string &str, MathStructure &vargs, const ParseOptions &po=default_parse_options)
 
size_t lastArgumentDefinitionIndex () const
 
ArgumentgetArgumentDefinition (size_t index)
 
void clearArgumentDefinitions ()
 
void setArgumentDefinition (size_t index, Argument *argdef)
 
int stringArgs (const string &str, vector< string > &svargs)
 
void setDefaultValue (size_t arg_, string value_)
 
const string & getDefaultValue (size_t arg_) const
 
void appendDefaultValues (MathStructure &vargs)
 
MathStructure produceVector (const MathStructure &vargs, int begin=-1, int end=-1)
 
MathStructure produceArgumentsVector (const MathStructure &vargs, int begin=-1, int end=-1)
 
virtual bool representsPositive (const MathStructure &, bool=false) const
 
virtual bool representsNegative (const MathStructure &, bool=false) const
 
virtual bool representsNonNegative (const MathStructure &, bool=false) const
 
virtual bool representsNonPositive (const MathStructure &, bool=false) const
 
virtual bool representsInteger (const MathStructure &, bool=false) const
 
virtual bool representsNumber (const MathStructure &, bool=false) const
 
virtual bool representsRational (const MathStructure &, bool=false) const
 
virtual bool representsReal (const MathStructure &, bool=false) const
 
virtual bool representsComplex (const MathStructure &, bool=false) const
 
virtual bool representsNonZero (const MathStructure &, bool=false) const
 
virtual bool representsEven (const MathStructure &, bool=false) const
 
virtual bool representsOdd (const MathStructure &, bool=false) const
 
virtual bool representsUndefined (const MathStructure &) const
 
virtual bool representsBoolean (const MathStructure &) const
 
virtual bool representsNonMatrix (const MathStructure &) const
 
- Public Member Functions inherited from ExpressionItem
 ExpressionItem (string cat_, string name_, string title_="", string descr_="", bool is_local=true, bool is_builtin=false, bool is_active=true)
 
virtual bool destroy ()
 
bool isRegistered () const
 
void setRegistered (bool is_registered)
 For internal use.
 
virtual const string & name (bool use_unicode=false, bool(*can_display_unicode_string_function)(const char *, void *)=NULL, void *can_display_unicode_string_arg=NULL) const
 
virtual const string & referenceName () const
 
virtual const ExpressionNamepreferredName (bool abbreviation=false, bool use_unicode=false, bool plural=false, bool reference=false, bool(*can_display_unicode_string_function)(const char *, void *)=NULL, void *can_display_unicode_string_arg=NULL) const
 
virtual const ExpressionNamepreferredInputName (bool abbreviation=false, bool use_unicode=false, bool plural=false, bool reference=false, bool(*can_display_unicode_string_function)(const char *, void *)=NULL, void *can_display_unicode_string_arg=NULL) const
 
virtual const ExpressionNamepreferredDisplayName (bool abbreviation=false, bool use_unicode=false, bool plural=false, bool reference=false, bool(*can_display_unicode_string_function)(const char *, void *)=NULL, void *can_display_unicode_string_arg=NULL) const
 
virtual const ExpressionNamegetName (size_t index) const
 
virtual void setName (const ExpressionName &ename, size_t index=1, bool force=true)
 
virtual void setName (string sname, size_t index, bool force=true)
 
virtual void addName (const ExpressionName &ename, size_t index=0, bool force=true)
 
virtual void addName (string sname, size_t index=0, bool force=true)
 
virtual size_t countNames () const
 
virtual void clearNames ()
 
virtual void clearNonReferenceNames ()
 
virtual void removeName (size_t index)
 
virtual size_t hasName (const string &sname, bool case_sensitive=true) const
 
virtual size_t hasNameCaseSensitive (const string &sname) const
 
virtual const ExpressionNamefindName (int abbreviation=-1, int use_unicode=-1, int plural=-1, bool(*can_display_unicode_string_function)(const char *, void *)=NULL, void *can_display_unicode_string_arg=NULL) const
 
virtual const string & title (bool return_name_if_no_title=true, bool use_unicode=false, bool(*can_display_unicode_string_function)(const char *, void *)=NULL, void *can_display_unicode_string_arg=NULL) const
 
virtual void setTitle (string title_)
 
virtual const string & description () const
 
virtual void setDescription (string descr_)
 
virtual const string & category () const
 
virtual void setCategory (string cat_)
 
virtual bool hasChanged () const
 
virtual void setChanged (bool has_changed)
 
virtual bool isLocal () const
 
virtual bool setLocal (bool is_local=true, int will_be_active=-1)
 
virtual bool isBuiltin () const
 
virtual bool isApproximate () const
 
virtual void setApproximate (bool is_approx=true)
 
virtual int precision () const
 
virtual void setPrecision (int prec)
 
virtual bool isActive () const
 
virtual void setActive (bool is_active)
 
virtual bool isHidden () const
 
virtual void setHidden (bool is_hidden)
 
virtual int refcount () const
 
virtual void ref ()
 
virtual void unref ()
 
virtual void ref (ExpressionItem *o)
 
virtual void unref (ExpressionItem *o)
 
virtual ExpressionItemgetReferencer (size_t index=1) const
 
virtual bool changeReference (ExpressionItem *o_from, ExpressionItem *o_to)
 

Protected Attributes

string sformula
 
string sformula_calc
 
vector< string > v_subs
 
vector< bool > v_precalculate
 
- Protected Attributes inherited from MathFunction
MathFunction_p * priv
 
int argc
 
int max_argc
 
vector< string > default_values
 
size_t last_argdef_index
 
string scondition
 
- Protected Attributes inherited from ExpressionItem
string scat
 
string stitle
 
string sdescr
 
bool b_local
 
bool b_changed
 
bool b_builtin
 
bool b_approx
 
bool b_active
 
bool b_registered
 
bool b_hidden
 
bool b_destroyed
 
int i_ref
 
int i_precision
 
vector< ExpressionItem * > v_refs
 
vector< ExpressionNamenames
 

Additional Inherited Members

- Protected Member Functions inherited from MathFunction
bool testArguments (MathStructure &vargs)
 
virtual MathStructure createFunctionMathStructureFromVArgs (const MathStructure &vargs)
 
virtual MathStructure createFunctionMathStructureFromSVArgs (vector< string > &svargs)
 

Detailed Description

A user defined mathematical function.

User functions are functions defined using expression strings, representing mathematical formulas.

The expression/formula of a function is basically a normal expression with placeholders for arguments. These placeholders consists of a backslash and a letter — x, y, z for the 1st, 2nd and 3rd arguments and a to u for argument 4 to 24. They are replaced by entered arguments when a function is calculated. The placeholders naturally also decide the number of arguments that a function requires. For example the function for triangle area ("base * height / 2") has the name triangle and the formula "(\x*\y)/2", which gives that "triangle(2, 3)" equals "(2*3) / 2" and returns "3" as result. An argument can be used more than one time and all arguments must not necessarily be in order in the formula.

Additionally, optional arguments can be put in the formula with upper-case (X, Y, Z, ...) instead of lower-case letters (x, y, z, ...). The default value can be put in brackets after the letter (ex. "\X{2}"). The default value may be omitted and is then zero. All additional arguments after an optional argument must also be optional.

To simplify the formula and make it more efficient, subfunctions can be used. These works just like the main formula, using the arguments of it. Subfunctions are referenced in the formula using ('\2', '\2', '\3', ...). Even though it would be quite meaningless, the formula for triangle function could for example have a subfunction "\x*\y" and the formula "\1/2". Subfunctions must be added before the main formula is set.

Member Function Documentation

◆ calculate()

int UserFunction::calculate ( MathStructure mstruct,
const MathStructure vargs,
const EvaluationOptions eo 
)
virtual

The main function for subclasses to reimplement. Calculates a value from arguments in vargs and puts it in mstruct.

This function expects the number of arguments to be equal to the maximum number of arguments, and checked by the argument definitions.

If the return value is negative, then argument -(return value) has been evaluated in mstruct. If -(return value) is greater than max arguments, then mstruct is a vector of evaluated argument values.

Parameters
[out]mstructStructure that is set with the result of the calculation.
vargsArguments passed to the mathematical function.
eoEvaluation options.
Returns
1 if the calculation was successful.

Reimplemented from MathFunction.

◆ formula()

string UserFunction::formula ( ) const

Returns the external representation of the formula.

◆ internalFormula()

string UserFunction::internalFormula ( ) const

Returns the internal representation of the formula.

◆ setFormula()

void UserFunction::setFormula ( string  new_formula,
int  argc_ = -1,
int  max_argc_ = 0 
)

Sets the formula of the mathematical function.

Parameters
new_formulaFormula/expression.
arc_Minimum number of arguments or -1 to read from formula.
max_argc_Maximum number of arguments (ignored if argc_ < 0)

◆ setSubfunction()

void UserFunction::setSubfunction ( size_t  index,
string  subfunction 
)

Sets the formula for a subfunction.

Parameters
indexIndex (starting at 1).
subfunctionFormula/expression.

◆ subtype()

int UserFunction::subtype ( ) const
virtual

Returns the subtype of the mathematical function, corresponding to which subsubclass the object belongs to.

Returns
FunctionSubtype.

Reimplemented from MathFunction.


The documentation for this class was generated from the following file: