BigInteger.Log Method
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Returns the logarithm of a specified number.
Log(BigInteger) |
Returns the natural (base |
Log(BigInteger, Double) |
Returns the logarithm of a specified number in a specified base. |
- Source:
- BigInteger.cs
- Source:
- BigInteger.cs
- Source:
- BigInteger.cs
Returns the natural (base e
) logarithm of a specified number.
public:
static double Log(System::Numerics::BigInteger value);
public static double Log (System.Numerics.BigInteger value);
static member Log : System.Numerics.BigInteger -> double
Public Shared Function Log (value As BigInteger) As Double
Parameters
- value
- BigInteger
The number whose logarithm is to be found.
Returns
The natural (base e
) logarithm of value
, as shown in the table in the Remarks section.
Exceptions
The natural log of value
is out of range of the Double data type.
Remarks
The value
parameter is specified as a base 10 number.
The precise return value of this method depends on the sign of value
, as the following table shows.
Sign of value parameter |
Return value |
---|---|
Positive | The natural logarithm of value ; that is, ln value , or log evalue . |
Zero | NegativeInfinity. |
Negative | NaN. |
To calculate the base 10 logarithm of a BigInteger value, call the Log10 method. To calculate the logarithm of a number in another base, call the Log(BigInteger, Double) method.
You can find the square root of a number by calling the Log method along with the Math.Exp method. Note that the result is Double.PositiveInfinity if the result is greater than Double.MaxValue. The following example calculates the square root of each element in an array of BigInteger values.
using System;
using System.Numerics;
public class Example
{
public static void Main()
{
BigInteger[] values = { 2, 100, BigInteger.Pow(1000, 100),
BigInteger.Pow(2, 64) };
foreach (var value in values)
Console.WriteLine("The square root of {0} is {1}", value,
Math.Exp(BigInteger.Log(value) / 2));
}
}
// The example displays the following output:
// The square root of 2 is 1.41421356237309
// The square root of 100 is 10
// The square root of 1000000000000000000000000000000000000000000000000000000000000
// 00000000000000000000000000000000000000000000000000000000000000000000000000000000
// 00000000000000000000000000000000000000000000000000000000000000000000000000000000
// 00000000000000000000000000000000000000000000000000000000000000000000000000000000
// is 9.99999999999988E+149
// The square root of 18446744073709551616 is 4294967296
open System
open System.Numerics
let values = [| 2I; 100I; BigInteger.Pow(1000I, 100); BigInteger.Pow(2I, 64) |]
for value in values do
printfn $"The square root of {value} is {Math.Exp(BigInteger.Log(value) / 2.)}"
// The example displays the following output:
// The square root of 2 is 1.41421356237309
// The square root of 100 is 10
// The square root of 1000000000000000000000000000000000000000000000000000000000000
// 00000000000000000000000000000000000000000000000000000000000000000000000000000000
// 00000000000000000000000000000000000000000000000000000000000000000000000000000000
// 00000000000000000000000000000000000000000000000000000000000000000000000000000000
// is 9.99999999999988E+149
// The square root of 18446744073709551616 is 4294967296
Imports System.Numerics
Module Example
Public Sub Main()
Dim values() As BigInteger = { 2, 100, BigInteger.Pow(1000, 100),
BigInteger.Pow(2, 64) }
For Each value In values
Console.WriteLine("The square root of {0} is {1}", value,
Math.Exp(BigInteger.Log(value) / 2))
Next
End Sub
End Module
' The example displays the following output:
' The square root of 2 is 1.41421356237309
' The square root of 100 is 10
' The square root of 1000000000000000000000000000000000000000000000000000000000000
' 00000000000000000000000000000000000000000000000000000000000000000000000000000000
' 00000000000000000000000000000000000000000000000000000000000000000000000000000000
' 00000000000000000000000000000000000000000000000000000000000000000000000000000000
' is 9.99999999999988E+149
' The square root of 18446744073709551616 is 4294967296
This method corresponds to the Math.Log(Double) method for the primitive numeric types.
See also
Applies to
.NET 9 and other versions
Product | Versions |
---|---|
.NET | Core 1.0, Core 1.1, Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9 |
.NET Framework | 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |
.NET Standard | 1.1, 1.2, 1.3, 1.4, 1.6, 2.0, 2.1 |
UWP | 10.0 |
- Source:
- BigInteger.cs
- Source:
- BigInteger.cs
- Source:
- BigInteger.cs
Returns the logarithm of a specified number in a specified base.
public:
static double Log(System::Numerics::BigInteger value, double baseValue);
public static double Log (System.Numerics.BigInteger value, double baseValue);
static member Log : System.Numerics.BigInteger * double -> double
Public Shared Function Log (value As BigInteger, baseValue As Double) As Double
Parameters
- value
- BigInteger
A number whose logarithm is to be found.
- baseValue
- Double
The base of the logarithm.
Returns
The base baseValue
logarithm of value
, as shown in the table in the Remarks section.
Exceptions
The log of value
is out of range of the Double data type.
Remarks
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.
See also
Applies to
.NET 9 and other versions
Product | Versions |
---|---|
.NET | Core 1.0, Core 1.1, Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9 |
.NET Framework | 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |
.NET Standard | 1.1, 1.2, 1.3, 1.4, 1.6, 2.0, 2.1 |
UWP | 10.0 |
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