/**
* Call this function to resolve variables and init the function. May throw MyError
* (InvalidFunction).
*/
public void initFunction() {
// replace function variables in tree
for (int i = 0; i < fVars.length; i++) {
FunctionVariable fVar = fVars[i];
// look for Variable objects with name of function variable and
// replace them
int replacements = expression.replaceVariables(fVar.getSetVarString(), fVar);
isConstantFunction = isConstantFunction && replacements == 0;
if (replacements == 0) {
// x, y got polynomials while parsing
replacements = expression.replacePolynomials(fVar);
isConstantFunction = isConstantFunction && replacements == 0;
}
}
// replace variable names by objects
expression.resolveVariables();
// the idea here was to allow something like: Derivative[f] + 3x
// but wrapping the GeoFunction objects as ExpressionNodes of type
// FUNCTION
// leads to Derivative[f](x) + 3x
// expression.wrapGeoFunctionsAsExpressionNode();
// replace all polynomials in expression (they are all equal to "1x" if
// we got this far)
// by an instance of MyDouble
// simplify constant parts in expression
expression.simplifyConstantIntegers();
// evaluate expression to find out about the type of function
ExpressionValue ev;
try {
ev = expression.evaluate();
} catch (MyError err) {
// Evaluation failed: DESPERATE MODE
try {
// try to fix structure of expression and then try evaluation again
fixStructure();
ev = expression.evaluate();
} catch (Throwable th) {
// throw original error when desperate mode failed
throw err;
}
}
// initialize type as boolean or numeric function
initType(ev);
}
