graph

Class ParseFunction

java.lang.Object

graph.ScanString

graph.ParseFunction

All Implemented Interfaces:

Serializable

public class ParseFunction
extends ScanString
implements Serializable

This class will parse a function definition and solve it returning the value. The function may have upto 3 independent variables in it (x,y,z).

Known Bugs This class is not fool proof. If the answer is wrong then use the parenthesis to force the order of evaluation. The most likely place this will be needed is in the use of the power command. The exponent is not evaluated correctly if it begins with a unary operator.

List of recognised commands

• ( ) parenthesis , comma
• +, -, unary -, unary +
• *, /
• ^ (raise to a power)
• pi, e, All the constants in class SpecialFunction
• log
• sin, cos, tan
• asin, acos, atan
• sqrt
• rand
• exp
• remainder
• atan2
• All the functions in class SpecialFunction
• Independent variables x,y,z
• Scientific notation using "e", "E", "d", "D".

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
boolean	debug Debug variable.

Fields inherited from class graph.ScanString

EOS, ERROR, NUMBER, nval, sval, UNKNOWN

Constructor Summary

Constructors

Constructor and Description
ParseFunction() Instantiate the class
ParseFunction(String s) Instantiate the class and define the string to parse.

Method Summary

Modifier and Type	Method and Description
double	getResult() Return the solution of the function if it has no independent values or they have already been set using the set methods
double	getResult(double x) Return the solution of the function given the independent values
double	getResult(double x, double y) Return the solution of the function given the independent values
double	getResult(double x, double y, double z) Return the solution of the function given the independent values
double[]	getResults(int n, double[] x) Return an array of solutions given an array of x values
double[]	getResults(int n, double[] x, double[] y) Return an array of solutions given an array of x values and y values
double[]	getResults(int n, double[] x, double[] y, double[] z) Return an array of solutions given an array of x values, y values and z values.
boolean[]	getVariables() Return a boolean array with index 0 true if the independent variable x was found in the function, index 1 true if y was found, and index 2 true if z was found.
boolean	parse() Parse the previously set string
boolean	parse(String s) Parse the string.
void	setIndepVariables(boolean ix, boolean iy, boolean iz) Set independent variables
void	setX(double x) Set the value of the independent variable X.
void	setY(double y) Set the value of the independent variable Y.
void	setZ(double z) Set the value of the independent variable Z.

Methods inherited from class graph.ScanString

addKeyWord, getKeyValue, nextWord, resetKeyWords, setString

Methods inherited from class java.lang.Object

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

Field Detail

debug

public boolean debug

Debug variable. If set true debug output is printed.

Constructor Detail

ParseFunction

public ParseFunction()

Instantiate the class

ParseFunction

public ParseFunction(String s)

Instantiate the class and define the string to parse.

Parameters:

s - The string to be parsed.

Method Detail

parse

public boolean parse(String s)

Parse the string.

Parameters:

s - The string to parse

Returns:

true if it was successful, false otherwise.

parse

public boolean parse()

Parse the previously set string

Returns:

true if it was successful, false otherwise.

getResult

public double getResult(double x,
                        double y,
                        double z)
                 throws Exception

Return the solution of the function given the independent values

Parameters:

x - indpendent x value

y - indpendent y value

z - indpendent z value

Returns:

solution of the function

Throws:

Exception

getResult

public double getResult(double x,
                        double y)
                 throws Exception

Return the solution of the function given the independent values

Parameters:

x - indpendent x value

y - indpendent y value

Returns:

solution of the function

Throws:

Exception

getResult

public double getResult(double x)
                 throws Exception

Return the solution of the function given the independent values

Parameters:

x - indpendent x value

Returns:

solution of the function

Throws:

Exception

getResult

public double getResult()
                 throws Exception

Return the solution of the function if it has no independent values or they have already been set using the set methods

Returns:

solution of the function

Throws:

Exception

See Also:

ParseFunction.setX(), ParseFunction.setY(), ParseFunction.setZ()

getResults

public double[] getResults(int n,
                           double[] x)
                    throws Exception

Return an array of solutions given an array of x values

Parameters:

n - number of values to process in the input array

x - Array containing the x values.

Returns:

Array containing the solutions.

Throws:

Exception - Generic exception if the array index n<=0, or x is null.

getResults

public double[] getResults(int n,
                           double[] x,
                           double[] y)
                    throws Exception

Return an array of solutions given an array of x values and y values

Parameters:

n - number of values to process in the input array

x - Array containing the x values.

y - Array containing the y values.

Returns:

Array containing the solutions.

Throws:

Exception - Generic exception if the array index n<=0, or x is null, or y is null.

getResults

public double[] getResults(int n,
                           double[] x,
                           double[] y,
                           double[] z)
                    throws Exception

Return an array of solutions given an array of x values, y values and z values.

Parameters:

n - number of values to process in the input array

x - Array containing the x values.

y - Array containing the y values.

Returns:

Array containing the solutions.

Throws:

Exception - Generic exception if the array index n<=0, or x is null, or y is null, or z is null.

getVariables

public boolean[] getVariables()

Return a boolean array with index 0 true if the independent variable x was found in the function, index 1 true if y was found, and index 2 true if z was found.

setX

public void setX(double x)

Set the value of the independent variable X.

setY

public void setY(double y)

Set the value of the independent variable Y.

setZ

public void setZ(double z)

Set the value of the independent variable Z.

setIndepVariables

public void setIndepVariables(boolean ix,
                              boolean iy,
                              boolean iz)

Set independent variables