Delphi Basics : Ln command

DelphiBasics

Ln
Function

Gives the natural logarithm of a number

System unit

function Ln(Number Extended):Extended;

Description

The Ln function takes an integer or floating point Number and gives the natural logarithm of that number.

This is only used for mathematical processing.

Ln has the opposite effect to Exp - the exponent of a number. (2.72 raised to that number power).

Related commands

Exp		Gives the exponent of a number
Log10		Gives the log to base 10 of a number

Download this web site as a Windows program.

Example code : Calculate the exponent of 2 and the natural log of the result

var
  float : Double;
begin
  // Get the natural logarithm of 2
  float := Ln(2);

  // Show this value
  ShowMessage('Ln(2) = '+FloatToStr(float));

  // Get the exponent of this value - reverses the Ln operation
  float := Exp(float);

  // Show this value
  ShowMessage('Exp(Ln(2)) = '+FloatToStr(float));
end;

Show full unit code

Ln(2) = 0.693147180559945
Exp(Ln(2)) = 2