/**
* Evaluates a valid expression and returns the resulting String in GeoGebra notation.
*
* @param casInput: in GeoGebraCAS syntax
* @param useGeoGebraVariables: whether GeoGebra objects should be substituted before evaluation
* @return evaluation result
* @throws Throwable
*/
public String evaluateGeoGebraCAS(ValidExpression casInput, boolean useGeoGebraVariables)
throws Throwable {
// convert parsed input to Maxima string
String MaximaString = toMaximaString(casInput, useGeoGebraVariables);
// Maxima simplification is turned off by default using simp:false;
// We turn it on here using ev(command, simp) when KeepInput is not used
if (!casInput.isKeepInputUsed()) {
StringBuilder sb = new StringBuilder();
sb.append("ev(");
sb.append(MaximaString);
sb.append(",simp)");
MaximaString = sb.toString();
}
// EVALUATE input in Maxima
String result = evaluateMaxima(MaximaString);
// convert Maxima result back into GeoGebra syntax
String ggbString = toGeoGebraString(result);
// TODO: remove
System.out.println("eval with Maxima: " + MaximaString);
System.out.println(" result: " + result);
System.out.println(" ggbString: " + ggbString);
return ggbString;
}
/**
* Evaluates the given ExpressionValue and returns the result in MathPiper syntax.
*
* @param resolveVariables: states whether variables from the GeoGebra kernel should be used. Note
* that this changes the given ExpressionValue.
*/
public synchronized String toMaximaString(ValidExpression ve, boolean resolveVariables) {
// resolve global variables
if (resolveVariables) {
casParser.resolveVariablesForCAS(ve);
}
// convert to Maxima String
String MaximaStr = doToMaximaString(ve, resolveVariables);
// handle assignments
String veLabel = ve.getLabel();
if (veLabel != null) {
StringBuilder sb = new StringBuilder();
if (ve instanceof FunctionNVar) {
// function, e.g. f(x) := 2*x
FunctionNVar fun = (FunctionNVar) ve;
sb.append(veLabel);
sb.append("(");
sb.append(fun.getVarString());
sb.append(") := ");
// evaluate right hand side:
// import for e.g. g(x) := Eval(D(x) x^2)
// sb.append("Eval(");
sb.append(MaximaStr);
// sb.append(")");
MaximaStr = sb.toString();
} else {
// assignment, e.g. a := 5
MaximaStr = veLabel + " := " + MaximaStr;
}
}
// TODO: remove
// System.out.println("CASmaxima.toMaxima: " + MaximaStr);
return MaximaStr;
}
