Package com.singularsys.extensions.djep

Class DJep

java.lang.Object
com.singularsys.jep.Jep
com.singularsys.extensions.xjep.XJep
com.singularsys.extensions.djep.DJep
All Implemented Interfaces:
Serializable
Direct Known Subclasses:
MDJep
public class DJep extends XJep
Adds differentiation facilities to Jep. For example 
 DJep j = new DJep();
 j.addStandardDiffRules();
 ....
 Node node = j.parse("x^3");
 Node diff = j.differentiate(node,"x");
 Node simp = j.simplify(diff);
 j.println(simp);
 Node node2 = j.parse("diff(x^4,x)");
 Node proc = j.preprocess(node2);
 Node simp2 = j.simplify(proc);
 j.println(simp2);
Author:
Rich Morris Created on 16-Nov-2003
See Also:

  • Field Details

  • Constructor Details

    • DJep

      public DJep()
      Standard constructor. Use this instead of Jep or Jep if differentiation facilities are required.

    • DJep

      public DJep(JepComponent... components)

    • DJep

      public DJep(ComponentSet dJepComponents)

  • Method Details

    • setXComponentInternal

      protected void setXComponentInternal(JepComponent comp)
      Overrides:
      setXComponentInternal in class XJep

    • getDifferentiationVisitor

      public DifferentiationVisitor getDifferentiationVisitor()
      Returns the visitor used for differentiation. Allows more advanced functions.

    • addStandardDiffRules

      public boolean addStandardDiffRules()
      Adds the standard set of differentiation rules. Corresponds to all standard functions in the Jep plus a few more. 
       sin,cos,tan,asin,acos,atan,sinh,cosh,tanh,asinh,acosh,atanh
 sqrt,log,ln,abs,angle
 sum,im,re are handled separately.
 rand and mod currently un-handled

 Also adds rules for functions not in Jep function list:
        sec,cosec,cot,exp,pow,sgn
      Returns:
      false on error

    • addDiffRule

      public void addDiffRule(DiffRulesI rule)
      Adds a rule with instruction on how to differentiate a function.
      Parameters:
      rule -

    • differentiate

      public Node differentiate(Node node, String name) throws ParseException
      Differentiate an equation with respect to a variable.
      Parameters:
      node - top node of the expression tree to differentiate.
      name - differentiate with respect to this variable.
      Returns:
      the top node of a new parse tree representing the derivative.
      Throws:
      ParseException
      IllegalArgumentException

    • replacePartialDerivativeByExpressions

      public Node replacePartialDerivativeByExpressions(Node node) throws JepException
      Replace any partial derivatives found in the expression by their expressions.
      Parameters:
      node - expression to process, may be modified
      Returns:
      the expression after replacement
      Throws:
      JepException

    • differentiate

      public DVariable differentiate(DVariable var, String... names) throws ParseException
      Finds the derivative of a differentiable variable. Will look up existing derivative if it exists or calculate the derivative if needed.
      Parameters:
      var - variable to differentiate
      names - names of the partial derivatives to find, either a single name "x" or an array of names to find higher derivatives
      Returns:
      a variable representing the partial derivative
      Throws:
      ParseException