org.matheclipse.core.reflection.system

Class RowReduce

java.lang.Object

org.matheclipse.core.eval.interfaces.AbstractEvaluator

org.matheclipse.core.eval.interfaces.AbstractFunctionEvaluator

org.matheclipse.core.reflection.system.RowReduce

All Implemented Interfaces:

IFunctionEvaluator, IEvaluator

public class RowReduce
extends AbstractFunctionEvaluator

Reduce the matrix to row reduced echelon form.

See:

• Wikipedia - Row echelon form
• Solving Systems of Linear Equations; Row Reduction

Constructor Summary

Constructors

Constructor and Description
RowReduce()

Method Summary

Modifier and Type	Method and Description
IExpr	evaluate(IAST ast, EvalEngine engine) Symbolic evaluation of a function.
static IAST	rowReduced2List(org.apache.commons.math4.linear.FieldMatrix matrix, EvalEngine engine) Return the solution of the given (augmented-)matrix interpreted as a system of linear equations
static IAST	rowReduced2RulesList(org.apache.commons.math4.linear.FieldMatrix matrix, IAST variableList, IAST resultList) Row reduce the given (augmented-)matrix and append the result as rules for the given variableList.

Methods inherited from class org.matheclipse.core.eval.interfaces.AbstractFunctionEvaluator

createRuleFromMethod, getNormalizedNegativeExpression, getNormalizedNegativeExpression, getPeriodicParts, getPureImaginaryPart, getRuleAST, initSerializedRules, isNegativeExpression, setUp

Methods inherited from class org.matheclipse.core.eval.interfaces.AbstractEvaluator

numericEval

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

RowReduce

public RowReduce()

Method Detail

evaluate

public IExpr evaluate(IAST ast,
                      EvalEngine engine)

Description copied from class: AbstractFunctionEvaluator

Symbolic evaluation of a function. ast.get(0) (or alternatively ast.head()) contains the head (i.e. the function symbol) of this abstract syntax tree (AST).
From ast.arg1() to ast.get(n) the ast contains the first to n-th argument of the function (alternatively you get the first to fifth argument with the methods arg1(), arg2(),... arg5()).
If necessary use the methods from the Validate class to check the number or types of arguments in the evaluate method.
Note: if the symbolic evaluation isn't possible or no result is found the evaluate method returns with a null value without throwing an exception!

Specified by:

evaluate in interface IFunctionEvaluator

Specified by:

evaluate in class AbstractFunctionEvaluator

Parameters:

ast - the abstract syntax tree (AST) which should be evaluated

engine - the users current evaluation engine

Returns:

the evaluated object or null, if evaluation isn't possible

See Also:

Validate, IExpr.head(), IAST.arg1(), IAST.arg2(), IAST.arg3()

rowReduced2List

public static IAST rowReduced2List(org.apache.commons.math4.linear.FieldMatrix matrix,
                                   EvalEngine engine)

Return the solution of the given (augmented-)matrix interpreted as a system of linear equations

Parameters:

matrix -

Returns:

F.NIL if the linear system is inconsistent and has no solution

rowReduced2RulesList

public static IAST rowReduced2RulesList(org.apache.commons.math4.linear.FieldMatrix matrix,
                                        IAST variableList,
                                        IAST resultList)

Row reduce the given (augmented-)matrix and append the result as rules for the given variableList.

Parameters:

matrix - a (augmented-)matrix

variableList - list of variable symbols

resultList - a list to which the rules should be appended

Returns:

resultList with the appended results as list of rules