Math.Log10 Method (System)

Log10 Method

.NET Framework Class Library

Math..::.Log10 Method

Updated: August 2008

Returns the base 10 logarithm of a specified number.

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

Syntax

Visual Basic (Declaration)

Public Shared Function Log10 ( _
    d As Double _
) As Double

Visual Basic (Usage)

Dim d As Double
Dim returnValue As Double

returnValue = Math.Log10(d)

public static double Log10(
    double d
)

Visual C++

public:
static double Log10(
    double d
)

JScript

public static function Log10(
    d : double
) : double

Parameters

d: Type: System..::.Double
A number whose logarithm is to be found.

Return Value

Type: System..::.Double

Sign of d	Returns
Positive	The base 10 log of d; that is, log 10 d.
Zero	NegativeInfinity
Negative	NaN

If d is equal to NaN, this method returns NaN. If d is equal to PositiveInfinity, this method returns PositiveInfinity.

Remarks

Parameter d is specified as a base 10 number.

Examples

The following example uses Log10 to return the base 10 logarithm of selected values.

Visual Basic

Module Example
   Public Sub Main()
      Dim numbers() As Double = {-1, 0, .105, .5, .798, 1, 4, 6.9, 10, 50, _
                                 100, 500, 1000, Double.MaxValue}

      For Each number As Double In numbers
         Console.WriteLine("The natural log of {0} is {1}.", _
                           number, Math.Log10(number))
      Next
   End Sub
End Module
' The example displays the following output:
'       The natural log of -1 is NaN.
'       The natural log of 0 is -Infinity.
'       The natural log of 0.105 is -0.978810700930062.
'       The natural log of 0.5 is -0.301029995663981.
'       The natural log of 0.798 is -0.0979971086492706.
'       The natural log of 1 is 0.
'       The natural log of 4 is 0.602059991327962.
'       The natural log of 6.9 is 0.838849090737255.
'       The natural log of 10 is 1.
'       The natural log of 50 is 1.69897000433602.
'       The natural log of 100 is 2.
'       The natural log of 500 is 2.69897000433602.
'       The natural log of 1000 is 3.
'       The natural log of 1.79769313486232E+308 is 308.254715559917.

using System;

public class Example
{
   public static void Main()
   {
      double[] numbers = {-1, 0, .105, .5, .798, 1, 4, 6.9, 10, 50, 
                          100, 500, 1000, Double.MaxValue};

      foreach (double number in numbers)
         Console.WriteLine("The natural log of {0} is {1}.", 
                           number, Math.Log10(number));
   }
}
// The example dislays the following output:
//       The natural log of -1 is NaN.
//       The natural log of 0 is -Infinity.
//       The natural log of 0.105 is -0.978810700930062.
//       The natural log of 0.5 is -0.301029995663981.
//       The natural log of 0.798 is -0.0979971086492706.
//       The natural log of 1 is 0.
//       The natural log of 4 is 0.602059991327962.
//       The natural log of 6.9 is 0.838849090737255.
//       The natural log of 10 is 1.
//       The natural log of 50 is 1.69897000433602.
//       The natural log of 100 is 2.
//       The natural log of 500 is 2.69897000433602.
//       The natural log of 1000 is 3.
//       The natural log of 1.79769313486232E+308 is 308.254715559917.

Platforms

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC, Xbox 360, Zune

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

Version Information