public static String calcOneOperand(String operator, String operand) {
		if(operator.equals("|")) {
			return String.valueOf(abs(Double.valueOf(operand)));
		} else if(operator.equals("v")) {
			return String.valueOf(sqrt(Double.valueOf(operand)));
		} else if(operator.equals("~")) {
			return String.valueOf(round(Double.valueOf(operand)));
		} else if(operator.equals("s")) {
			return String.valueOf(sin(Double.valueOf(operand)));
		} else if(operator.equals("c")) {
			return String.valueOf(cos(Double.valueOf(operand)));
		} else if(operator.equals("t")) {
			return String.valueOf(tan(Double.valueOf(operand)));
		} else {
			return null;
		}
	}