/**
* Evaluate a function at a specific point for one single variable. Evaluation is done between
* xmin and xmax. It is assumed that there are no any other variable involved
*
* @param indvars Define independent variable, like 'x' Only one variable is allowed
* @param xmin xmin value for independent varible
* @param xmax xmax value for independent varible
* @return true if no errors
*/
public boolean eval(String indvars, double xmin, double xmax) {
boolean suc = true;
String name = proxy.getName();
int points = proxy.getPoints();
double min = xmin;
double max = xmax;
x = new double[points];
y = new double[points];
for (int i = 0; i < points; i++) {
x[i] = min + i * (max - min) / (points - 1);
jep.addVariable(indvars.trim(), x[i]);
try {
Object result = jep.evaluate(node);
if (result instanceof Double) {
y[i] = ((Double) jep.evaluate(node)).doubleValue();
}
} catch (ParseException e) {
jhplot.utils.Util.ErrorMessage(
"Failed to parse function " + name + " Error:" + e.toString());
suc = false;
}
}
if (suc) isEvaluated = true;
return suc;
} // end 1-D evaluation
/**
* Create a function in any dimension evaluation.
*
* <p>The function may have many independent variables.
*
* <p>
*
* <h3>List of commands</h3>
*
* <ul>
* <li>( ) parenthesis , comma
* <li>+, -, unary -, unary +
* <li>*, /
* <li>^ (raise to a power)
* <li>pi, e, All the constants in class SpecialFunction
* <li>log
* <li>sin, cos, tan, sinh, cosh, tanh
* <li>asin, acos, atan, asinh, acosh, atanh
* <li>sqrt
* <li>rand
* <li>exp
* <li>remainder
* <li>atan2
* <li>Special functions and constants. Look at the book
* <li>All the functions in class SpecialFunction
* <li>Independent variables x
* <li>Scientific notation using "e", "E", "d", "D".
* </ul>
*
* @prama title Title of the function
* @param name String representing the function
* @param vars String representing variables. Each variable should be separated by a comma.
* Example "x,y,z"
*/
public FND(String title, String name, String vars) {
this.title = title;
proxy = new FProxy(3, title, name, null, new double[] {0, 0, 0, 0, 0, 0}, maxpoints, true);
name = proxy.getName();
proxy.setVariables(vars);
setTitle(title);
lpp.setType(LinePars.F1D);
jep = new XJep();
jep.addStandardConstants();
jep.addStandardFunctions();
jep.setAllowUndeclared(true);
jep.setImplicitMul(true);
jep.setAllowAssignment(true);
// get all variables
avars = vars.split(",");
for (int i = 0; i < avars.length; i++) {
jep.addVariable(avars[i].trim(), 0);
}
jep.addVariable("x", 0);
try {
node = jep.parse(name);
processed = jep.preprocess(node);
} catch (ParseException e) {
} catch (Exception e) {
ErrorMessage("Error in parsing " + name);
}
}
/**
* Initialize function from proxy.
*
* @param f
*/
public FND(FProxy f) {
proxy = f;
String name = proxy.getName();
if (proxy.getType() != 4) {
ErrorMessage("Error in parsing FND. Wrong type! " + name);
return;
}
setTitle(proxy.getTitle());
lpp.setType(LinePars.F1D);
jep = new XJep();
jep.addStandardConstants();
jep.addStandardFunctions();
jep.setAllowUndeclared(true);
jep.setImplicitMul(true);
jep.setAllowAssignment(true);
// get all variables
String vars = proxy.getVariables();
avars = vars.split(",");
for (int i = 0; i < avars.length; i++) {
jep.addVariable(avars[i].trim(), 0);
}
jep.addVariable("x", 0);
try {
node = jep.parse(name);
processed = jep.preprocess(node);
} catch (ParseException e) {
} catch (Exception e) {
ErrorMessage("Error in parsing " + name);
}
}
/** Treat the function as complex. */
public void simplify() {
String name = proxy.getName();
try {
simp = jep.simplify(processed);
} catch (ParseException e) {
} catch (Exception e) {
ErrorMessage("Error in simplification of " + name);
}
}
/**
* Evaluate a function at a specific point for one single variable. Evaluation is done between
* xmin and xmax
*
* @param indvars Define independent variable, like 'x' Only one variable is allowed
* @param xmin xmin value for independent varible
* @param xmax xmax value for independent varible
* @param vars define values for other variables, like 'y=1,z=3'
* @return true if no errors
*/
public boolean eval(String indvars, double xmin, double xmax, String vars) {
String name = proxy.getName();
int points = proxy.getPoints();
boolean suc = true;
String[] tmp = vars.split(",");
// double[] vd = new double[tmp.length];
fixedVars = vars;
for (int i = 0; i < tmp.length; i++) {
String[] vv = tmp[i].split("=");
if (vv.length != 2) {
ErrorMessage("Error in parsing list of input variablse. Did you use val=number? ");
}
try {
double d = Double.valueOf(vv[1].trim()).doubleValue();
jep.addVariable(vv[0].trim(), d);
} catch (NumberFormatException nfe) {
System.out.println("NumberFormatException: " + nfe.getMessage());
suc = false;
}
}
double min = xmin;
double max = xmax;
x = new double[points];
y = new double[points];
for (int i = 0; i < points; i++) {
x[i] = min + i * (max - min) / (points - 1);
jep.addVariable(indvars.trim(), x[i]);
try {
Object result = jep.evaluate(node);
if (result instanceof Double) {
y[i] = ((Double) jep.evaluate(node)).doubleValue();
}
} catch (ParseException e) {
jhplot.utils.Util.ErrorMessage(
"Failed to parse function " + name + " Error:" + e.toString());
suc = false;
}
}
if (suc) isEvaluated = true;
return suc;
} // end 1-D evaluation
/**
* differentiate the expression and simplify
*
* @param var variable used for differentiation
*/
public void diff(String var) {
String name = proxy.getName();
DJep j = new DJep();
j.addStandardConstants();
j.addStandardFunctions();
j.addComplex();
j.setAllowUndeclared(true);
j.setAllowAssignment(true);
j.setImplicitMul(true);
// Sets up standard rules for differentiating sin(x) etc.
j.addStandardDiffRules();
try {
// parse the string
node = j.parse(name);
diff = j.differentiate(node, var);
simp = j.simplify(diff);
} catch (ParseException e) {
ErrorMessage("Error in parsing " + name);
}
}
/**
* Get the name of the function used for evaluation
*
* @return Name
*/
public String getName() {
return proxy.getName();
}