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BigInteger::Log Method (BigInteger, Double)

Returns the logarithm of a specified number in a specified base.

Namespace:  System.Numerics
Assembly:  System.Numerics (in System.Numerics.dll)

public:
static double Log(
	BigInteger value, 
	double baseValue
)

Parameters

value
Type: System.Numerics::BigInteger
A number whose logarithm is to be found.
baseValue
Type: System::Double
The base of the logarithm.

Return Value

Type: System::Double
The base baseValue logarithm of value, as shown in the table in the Remarks section.

ExceptionCondition
ArgumentOutOfRangeException

The log of value is out of range of the Double data type.

The value and baseValue parameters are specified as base 10 numbers.

The precise return value of the method depends on the sign of value and on the sign and value of baseValue, as the following table shows.

value parameter

baseValue parameter

Return value

value > 0

(0 < baseValue < 1) -or-(baseValue > 1)

logbaseValue(value)

value < 0

(any value)

Double::NaN

(any value)

baseValue < 0

Double::NaN

value != 1

baseValue = 0

Double::NaN

value != 1

baseValue = Double::PositiveInfinity

Double::NaN

(any value)

baseValue = Double::NaN

Double::NaN

(any value)

baseValue = 1

Double::NaN

value = 0

0 < baseValue < 1

Double::PositiveInfinity

value = 0

baseValue > 1

Double::PositiveInfinity

value = 1

baseValue = 0

0

value = 1

baseValue = Double::PositiveInfinity

0

To calculate the base 10 logarithm of a BigInteger value, call the Log10 method. To calculate the natural logarithm of a number, call the Log(BigInteger) method.

This method corresponds to the Math::Log method for the primitive numeric types.

.NET Framework

Supported in: 4

.NET Framework Client Profile

Supported in: 4

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
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