Package org.tweetyproject.math.term

Class Term

java.lang.Object
org.tweetyproject.math.term.Term
Direct Known Subclasses:
AssociativeOperation, Constant, Difference, Fraction, FunctionalTerm, Variable
public abstract class Term extends Object
This class models a mathematical term.
Author:
Matthias Thimm

  • Constructor Details

    • Term

      public Term()

  • Method Details

    • add

      public Sum add​(Term t)
      Returns the sum of this and the given term.
      Parameters:
      t - a term
      Returns:
      the sum of this and the given term.

    • minus

      public Difference minus​(Term t)
      Returns the sum of this and (-1) * the given term.
      Parameters:
      t - a term
      Returns:
      the sum of this and (-1) * the given term.

    • mult

      public Product mult​(Term t)
      Returns the product of this and the given term.
      Parameters:
      t - a term.
      Returns:
      the product of this and the given term.

    • min

      public Term min​(Term t)
      Returns the minimum of this and the given term.
      Parameters:
      t - a term.
      Returns:
      the minimum of this and the given term.

    • value

      public abstract Constant value() throws IllegalArgumentException
      Computes the actual value of this term if it contains no variables.
      Returns:
      the value of this term, either a float or an integer.
      Throws:
      IllegalArgumentException - if this term contains at least on variable.

    • doubleValue

      public double doubleValue() throws IllegalArgumentException
      Computes the actual value of this term if it contains no variables.
      Returns:
      the double value of this term.
      Throws:
      IllegalArgumentException - if this term contains at least on variable.

    • isContinuous

      public abstract boolean isContinuous​(Variable v)
      Checks whether this term is continuous in v.
      Parameters:
      v - a variable
      Returns:
      "true" iff this term is continuous in v.

    • isContinuous

      public boolean isContinuous()
      Checks whether this term is continuous in all appearing variables.
      Returns:
      "true" iff this term is continuous in all appearing variables

    • getVariables

      public abstract Set<Variable> getVariables()
      Returns all variables in this term.
      Returns:
      all variables in this term.

    • getProducts

      public abstract Set<Product> getProducts()
      Returns all products of this term.
      Returns:
      all products of this term.

    • getSums

      public abstract Set<Sum> getSums()
      Returns all sums of this term.
      Returns:
      all sums of this term.

    • getMinimums

      public abstract Set<Minimum> getMinimums()
      Returns all minimums of this term.
      Returns:
      all minimums of this term.

    • getMaximums

      public abstract Set<Maximum> getMaximums()
      Returns all maximums of this term.
      Returns:
      all maximums of this term.

    • getAbsoluteValues

      public abstract Set<AbsoluteValue> getAbsoluteValues()
      Returns all absolute values of this term.
      Returns:
      all absolute values of this term.

    • isInteger

      public abstract boolean isInteger()
      Checks whether this term represents an integer value.
      Returns:
      "true" iff this term represents an integer value.

    • toLinearForm

      public abstract Sum toLinearForm() throws IllegalArgumentException
      Converts this term into a linear normal form, i.e. into a sum of products of a constant and a variable.
      Returns:
      a term in linear normal form.
      Throws:
      IllegalArgumentException - if this term cannot be converted into a linear normal form.

    • toQuadraticForm

      public abstract Sum toQuadraticForm() throws IllegalArgumentException
      Throws:
      IllegalArgumentException

    • replaceTerm

      public abstract Term replaceTerm​(Term toSubstitute, Term substitution)
      Replaces each occurrence of "toSubstitute" by "substitution" and return the new term.
      Parameters:
      toSubstitute - the term to be substituted
      substitution - the new term
      Returns:
      this term where "toSubstitute" is replaced by "substitution"

    • evaluateVector

      public static List<Double> evaluateVector​(List<Term> functions, Map<Variable,​? extends Term> mapping)
      Evaluates each function in the given list with the given values for variables.
      Parameters:
      functions - a list of functions
      mapping - a map mapping variables to terms
      Returns:
      the values

    • evaluateVector

      public static double[] evaluateVector​(List<Term> functions, double[] values, List<Variable> variables)
      Evaluates each function in the given list with the given values for variables.
      Parameters:
      functions - a list of functions
      values - the values of the variables
      variables - the (ordered) list of variables
      Returns:
      the values

    • evaluateMatrix

      public static double[][] evaluateMatrix​(List<List<Term>> functions, double[] values, List<Variable> variables)
      Evaluates each function in the given matrix with the given values for variables.
      Parameters:
      functions - a list of functions
      values - the values of the variables
      variables - the (ordered) list of variables
      Returns:
      the values

    • replaceAllTerms

      public Term replaceAllTerms​(double[] values, List<Variable> variables)
      Replaces terms according to the given map.
      Parameters:
      values - an array of values.
      variables - A list of variables that shall be substituted by the given values
      Returns:
      a term.

    • replaceAllTerms

      public Term replaceAllTerms​(Map<? extends Term,​? extends Term> substitutes)
      Replaces terms according to the given map.
      Parameters:
      substitutes - a map.
      Returns:
      a term.

    • isLinear

      public boolean isLinear()
      Checks whether this term is linear.
      Returns:
      "true" if this term is linear.

    • isQuadratic

      public boolean isQuadratic()
      Checks whether this term is quadratic.
      Returns:
      "true" if this term is quadratic.

    • simplify

      public abstract Term simplify()
      Simplifies this term in an equivalent way:
      - Replaces products that contain a zero by the constant zero
      - Removes a term one from products
      - Removes a term zero from sums
      - Aggregates constants in sums, products, and minimums
      - Evaluates functional terms on constants
      - Simplifies fractions where possible.
      Returns:
      the simplified term.

    • getTerms

      public abstract List<Term> getTerms()

    • derive

      public abstract Term derive​(Variable v) throws NonDifferentiableException
      Differentiates the term with respect to the given variable.
      Parameters:
      v - a variable.
      Returns:
      the derivation of this term wrt. the given variable.
      Throws:
      NonDifferentiableException - if the term cannot be differentiated.

    • collapseAssociativeOperations

      public abstract void collapseAssociativeOperations()
      This method collapses all associative operations appearing in this term, e.g. every min{min{a,b},c} becomes min{a,b,c}.

    • expandAssociativeOperations

      public abstract void expandAssociativeOperations()
      This method expands all associative operations appearing in this term, e.g. every min{a,b,c} becomes min{min{a,b},c}.

    • toString

      public abstract String toString()
      Overrides:
      toString in class Object