try
{
final TypeRegistry typeRegistry = context.getTypeRegistry();
n1 = typeRegistry.convertToNumber(parameters.getType(0), parameters.getValue(0));
n2 = typeRegistry.convertToNumber(parameters.getType(1), parameters.getValue(1));
n3 = typeRegistry.convertToNumber(parameters.getType(2), parameters.getValue(2));
} catch (NumberFormatException e)
{
throw EvaluationException.getInstance(LibFormulaErrorValue.ERROR_INVALID_ARGUMENT_VALUE);
}