private static Decimal DecimalSqrt(Decimal x, Decimal?guess = null)
{
Decimal valueOrDefault = guess.GetValueOrDefault(x / new Decimal(2));
Decimal num1 = x / valueOrDefault;
Decimal num2 = (valueOrDefault + num1) / new Decimal(2);
if (num2 == valueOrDefault)
{
return(num2);
}
return(Aggregates.DecimalSqrt(x, new Decimal?(num2)));
}
public static object StDev(FunctionContext context, IEnumerable data, ExpressionNode node)
{
IList <Decimal> numList = (IList <Decimal>) new List <Decimal>();
Decimal num1 = new Decimal(0);
foreach (object obj in Aggregates.NotNullValue(data, node, (object)context))
{
StorageType storageType = DataStorageHelper.GetStorageType(obj.GetType());
if (ExpressionNode.IsNumeric(storageType))
{
Decimal num2 = Convert.ToDecimal(obj);
num1 += num2;
numList.Add(num2);
}
else
{
if (storageType != StorageType.String && storageType != StorageType.SqlString)
{
throw new NotSupportedException("Standard deviation is not supported for type " + storageType.ToString());
}
Decimal result;
if (Decimal.TryParse(obj.ToString(), out result))
{
num1 += result;
numList.Add(result);
}
}
}
if (numList.Count == 0)
{
return((object)0);
}
Decimal num3 = num1 / (Decimal)numList.Count;
Decimal num4 = new Decimal(0);
foreach (Decimal num2 in (IEnumerable <Decimal>)numList)
{
Decimal num5 = num2 - num3;
Decimal num6 = num5 * num5;
num4 += num6;
}
return((object)Aggregates.DecimalSqrt(num4 / (Decimal)numList.Count, new Decimal?()));
}