private Enumerations.BinaryOperator GetBinaryOperator(string binaryOperator)
{
Enumerations.BinaryOperator binaryOp = Enumerations.BinaryOperator.Set;
if (binaryOperatorMap.Keys.Contains(binaryOperator))
{
binaryOp = binaryOperatorMap[binaryOperator];
}
else
{
binaryOp = Enumerations.BinaryOperator.Set;
}
return(binaryOp);
}
private void btnExecute_Click(object sender, EventArgs e)
{
TestDoubleExceptions();
if (String.IsNullOrEmpty(txtLeftOperand.Text) || String.IsNullOrWhiteSpace(txtLeftOperand.Text))
{
MessageBox.Show("Left operand is empty", _applicationName);
}
else if (String.IsNullOrEmpty(txtOperator.Text) || String.IsNullOrWhiteSpace(txtOperator.Text))
{
MessageBox.Show("Operator is empty", _applicationName);
}
else if (String.IsNullOrEmpty(txtRightOperand.Text) || String.IsNullOrWhiteSpace(txtRightOperand.Text))
{
MessageBox.Show("Right operand is empty", _applicationName);
}
else if (String.IsNullOrEmpty(txtPowerOf10.Text) || String.IsNullOrWhiteSpace(txtLeftOperand.Text))
{
MessageBox.Show("Rounding Power is empty", _applicationName);
}
else
{
double doubleLeft = System.Convert.ToDouble(txtLeftOperand.Text);
Enumerations.BinaryOperator binaryOperator = GetBinaryOperator(txtOperator.Text);
double doubleRight = System.Convert.ToDouble(txtRightOperand.Text);
int roundAtPowerOf10 = System.Convert.ToInt32(txtPowerOf10.Text);
double doubleResult = NumericHelper.BinaryOperate(
doubleLeft,
binaryOperator,
doubleRight,
GetRoundingStrategy(),
GetRoundAbsolute(),
roundAtPowerOf10);
txtResult.Text = System.Convert.ToString(doubleResult);
}
}
/// <summary>
/// Perform the required Binary Operation on the supplied value
/// </summary>
/// <param name="doubleValue">The value on which to perform the binary operation</param>
/// <param name="binaryOperator">The Binary Operation to be performed</param>
/// <param name="rightOperand">The right hand operand</param>
/// <param name="roundingStrategy">The rounding strategy</param>
/// <param name="roundAbsolute">Whether or not to round as for the abolute value</param>
/// <param name="roundAtPowerOf10">The power of 10 at which to perform rounding</param>
static public double BinaryOperate(double doubleValue,
Enumerations.BinaryOperator binaryOperator,
double rightOperand,
Enumerations.RoundingStrategy roundingStrategy,
bool roundAbsolute,
int roundAtPowerOf10)
{
double doubleResult = doubleValue;
// To conserve precision, where possible, try not to perform any "unity" operation
switch (binaryOperator)
{
case Enumerations.BinaryOperator.Set:
doubleResult = rightOperand;
break;
case Enumerations.BinaryOperator.Add:
// Do nothing if the right operand is indistinguishable from zero
if (!rightOperand.Equals(0.0))
{
doubleResult += rightOperand;
}
break;
case Enumerations.BinaryOperator.Subtract:
// Do nothing if the right operand is indistinguishable from zero
if (!rightOperand.Equals(0.0))
{
doubleResult -= rightOperand;
}
break;
case Enumerations.BinaryOperator.Multiply:
// Do nothing if the right operand is indistinguishable from unity
if (!rightOperand.Equals(1.0))
{
doubleResult *= rightOperand;
}
break;
case Enumerations.BinaryOperator.Divide:
if (Math.Abs(rightOperand) < DoubleValueEpsilon)
{
MessageBox.Show("Attempt to divide by zero", "Test Numeric");
}
// throw new AttemptToDivideByZeroException(String.Format("NumericHelper.BinaryOperate : An attempt was made to divide {0} by zero", doubleResult));
else
// Do nothing if the right operand is indistinguishable from unity
if (!rightOperand.Equals(1.0))
{
doubleResult /= rightOperand;
}
break;
default:
MessageBox.Show(String.Format("Binary Operator Enumeration Member {0} not defined", binaryOperator), "Test Numeric"); break;
// throw new BinaryOperatorUnrecognisedException(String.Format("NumericHelper.BinaryOperate : The Binary Operator Enumeration Member of value {0} was not recognised", binaryOperator));
}
if (roundingStrategy != Enumerations.RoundingStrategy.None)
{
// Perform rounding on the result
double roundingScaleFactor = 1.0 / PowerOf(10.0, roundAtPowerOf10);
bool negate = false;
if ((roundAbsolute) && (doubleResult < 0.0))
{
negate = true;
doubleResult = Math.Abs(doubleResult);
}
// Scale the number for rounding
doubleResult *= roundingScaleFactor;
switch (roundingStrategy)
{
case Enumerations.RoundingStrategy.Down:
// For negative numbers the .NET Runtime Truncate and Ceiling functions return the same values
// Math.Truncate( -1.5 ) -> -1.0 which is not what is required here
// Math.Ceiling( -1.5 ) -> -1.0
// So use Math.Floor for both negative and non-negative numbers
doubleResult = Math.Floor(doubleResult);
break;
case Enumerations.RoundingStrategy.Natural:
// Produce mid-point rounding that always goes to the nearest scaled integer-like double value
// Note that this has the effect of "round absolute" but that appears to be what most people expect!
doubleResult = Math.Round(doubleResult);
break;
case Enumerations.RoundingStrategy.Up:
// Use Math.Ceiling for both negative and non-negative numbers
doubleResult = Math.Ceiling(doubleResult);
break;
default:
MessageBox.Show(String.Format("Rounding Strategy {0} not defined", roundingStrategy), "Test Numeric");
// throw new RoundStrategyUnrecognisedException(String.Format("NumericHelper.BinaryOperate : The Roung Strategy Enumeration Member {0} was not recognised", roundingStrategy));
break;
}
// Get the number back
doubleResult /= roundingScaleFactor;
if (negate)
{
doubleResult = -doubleResult;
}
} // Perform rounding on the result
return(doubleResult);
}
