Returns the natural logarithm of a number. For an ErrorLogging object, this function can be used to write a string to the log file maintained by the object's container.
Description
Determines the natural logarithm of a number.
Syntax
Log ( n )
|
Argument |
Description |
|---|---|
|
n |
The number for which you want the natural logarithm (base e). The value of n must be greater than 0. |
Return value
Double.
Returns the natural logarithm of n. An execution error occurs if n is negative or zero. If n is null, Log returns null.
Inverse of Log
The inverse of the Log function is the Exp function.
Examples
This statement returns 2.302585092:
Log(10)
This statement returns -.693147. . .:
Log(0.5)
Both these statements result in an error at runtime:
Log(0) Log(-2)
After the following statements execute, the value of a is 200:
double a, b = Log(200) a = Exp(b)// a = 200
See also
Log method for DataWindows in the section called “Log” in DataWindow Reference.
Description
Writes a string to the log file maintained by the object's container.
Applies to
ErrorLogging objects
Syntax
errorlogobj.Log ( message )
|
Argument |
Description |
|---|---|
|
errorlogobj |
Reference to the ErrorLogging service instance |
|
message |
The text string you want to write to the log |
Return value
None.
Usage
The ErrorLogging object provides the ability to write messages to the log file used by the object's container.
Before you call the Log function, create an instance of the ErrorLogging service by calling the GetContextService function.
Examples
The following example shows how to write a string to the log for COM+:
ErrorLogging el
this.GetContextService("ErrorLogging", el)
el.log("Write this string to log")See also
