Log

Description

Calculates the natural logarithm of a number. Natural logarithms are based on the constant e (2.71828182845904).

Return value

The natural logarithm of a number.

Category

Mathematical functions

Syntax

Log(number) 

See also

Exp, Log10

Parameters

Parameter Description
number
Positive real number for which to calculate the natural logarithm

Example

<h3>Log Example</h3>

<cfif IsDefined("FORM.number")>
  <cfoutput>
    <p>Your number, #FORM.number#
    <br>#FORM.number# raised to the E power: #exp(FORM.number)#
    <cfif FORM.number LTE 0><br>Enter a positive real number to get its 
natural logarithm
      <cfelse><br>The natural logarithm   of #FORM.number#: #log(FORM.number)#
    </cfif>
    <cfif FORM.number LTE 0><br>Enter a positive real number to get its 
logarithm to base 10
      <cfelse><br>The logarithm of #FORM.number# to base 10: #log10(FORM.number)#
    </cfif>
  </cfoutput>
</cfif>
<cfform action = "log.cfm">
Enter a number to see its value raised to the E power, its natural logarithm, 
and the logarithm of number to base 10.
<cfinput type = "Text" name = "number" message = "You must enter a number"
validate = "float" required = "No">
<input type = "Submit" name = "">
</cfform>

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