public String deriveAt(double y) {
String first = "";
String second = "";
for (String s : fn) {
first += s;
first += (DELTA_X + y);
}
for (String s : fn) {
second += s;
second += y;
}
try {
Calculable evalFirst = new ExpressionBuilder(first).build();
Calculable evalSec = new ExpressionBuilder(second).build();
// double evalFirst = (Double)se.eval(first);
// double evalSec = (Double)se.eval(second);
DecimalFormat dm = new DecimalFormat("#.###");
double ans = ((evalFirst.calculate() - evalSec.calculate()) / DELTA_X);
return dm.format(ans);
} catch (Exception e) {
}
return "Error";
}
public double evaluar(double valor, boolean error)
throws UnknownFunctionException, UnparsableExpressionException {
double resultado = 0;
Calculable calc = this.parser.withVariable("x", valor).build();
resultado = calc.calculate();
return resultado;
}
public double evaulateAt(double x) {
String fnStr = "";
for (String s : fn) {
fnStr += s;
fnStr += x;
}
try {
Calculable eval = new ExpressionBuilder(fnStr).build();
return eval.calculate();
} catch (Exception e) {
}
return 0;
}
@Override
public Variable evaluate(SimulationStatus status) {
Calculable startCalc = buildExpression(startBuilder);
Calculable endCalc = buildExpression(endBuilder);
if (startCalc == null || endCalc == null) {
return new Variable("Unknown");
}
// Set the variables in the start and end calculators
for (FlightDataType type : status.getFlightData().getTypes()) {
double value = status.getFlightData().getLast(type);
startCalc.setVariable(new Variable(type.getSymbol(), value));
endCalc.setVariable(new Variable(type.getSymbol(), value));
}
// From the given datatype, get the time and function values and make an interpolator
// Note: must get in a way that flight data system will figure out units. Otherwise there will
// be a type conflict when we get the new data.
FlightDataType type = FlightDataType.getType(null, getSymbol(), null);
List<Double> data = status.getFlightData().get(type);
List<Double> time = status.getFlightData().get(FlightDataType.TYPE_TIME);
LinearInterpolator interp = new LinearInterpolator(time, data);
// Evaluate the expression to get the start and end of the range
double startTime, endTime;
try {
startTime = startCalc.calculate().getDoubleValue();
startTime = MathUtil.clamp(startTime, 0, Double.MAX_VALUE);
endTime = endCalc.calculate().getDoubleValue();
endTime = MathUtil.clamp(endTime, 0, time.get(time.size() - 1));
} catch (java.util.EmptyStackException e) {
log.info(
Markers.USER_MARKER,
"Unable to calculate time index for range expression "
+ getSymbol()
+ " due to empty stack exception");
return new Variable("Unknown");
}
// generate an array representing the range
double step = status.getSimulationConditions().getSimulation().getOptions().getTimeStep();
double[] t = ArrayUtils.range(startTime, endTime, step);
double[] y = new double[t.length];
int i = 0;
for (double tval : t) {
y[i] = interp.getValue(tval);
i++;
}
Variable result;
if (y.length == 0) {
result = new Variable("Unknown");
} else {
result = new Variable(hash(), y, startTime, step);
}
return result;
}