MathF.Log Method

Definition

Namespace:

System

Assembly:

System.Runtime.dll

Overloads

Log(Single)	Returns the natural (base e) logarithm of a specified number.
Log(Single, Single)	Returns the logarithm of a specified number in a specified base.

Log(Single)

Source:

MathF.cs

Returns the natural (base e) logarithm of a specified number.

public:
 static float Log(float x);

public static float Log (float x);

static member Log : single -> single

Public Shared Function Log (x As Single) As Single

Parameters

x

Single

The number whose logarithm is to be found.

Returns

Single

One of the values in the following table.

x parameter	Return value
Positive	The natural logarithm of x; that is, ln x, or log e x
Zero	NegativeInfinity
Negative	NaN
Equal to NaN	NaN
Equal to PositiveInfinity	PositiveInfinity

Remarks

Parameter x is specified as a base 10 number.

This method calls into the underlying C runtime, and the exact result or valid input range may differ between different operating systems or architectures.

See also

• E
• Exp(Single)

Log(Single, Single)

Source:

MathF.cs

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

public:
 static float Log(float x, float y);

public static float Log (float x, float y);

static member Log : single * single -> single

Public Shared Function Log (x As Single, y As Single) As Single

Parameters

x

Single

The number whose logarithm is to be found.

y

Single

The base.

Returns

Single

One of the values in the following table. (+Infinity denotes PositiveInfinity, -Infinity denotes NegativeInfinity, and NaN denotes NaN.)

x	newBase	Return value
x> 0	(0 <newBase< 1) -or-(newBase> 1)	lognewBase(a)
x< 0	(any value)	NaN
(any value)	newBase< 0	NaN
x != 1	newBase = 0	NaN
x != 1	newBase = +Infinity	NaN
x = NaN	(any value)	NaN
(any value)	newBase = NaN	NaN
(any value)	newBase = 1	NaN
x = 0	0 <newBase< 1	+Infinity
x = 0	newBase> 1	-Infinity
x = +Infinity	0 <newBase< 1	-Infinity
x = +Infinity	newBase> 1	+Infinity
x = 1	newBase = 0	0
x = 1	newBase = +Infinity	0

Remarks

This method calls into the underlying C runtime, and the exact result or valid input range may differ between different operating systems or architectures.