Node:Ln, Next:LoCase, Previous:library, Up:Reference

### Ln

#### Synopsis

    function Ln (x: Real): Real;

or

    function Ln (z: Complex): Complex;

#### Description

The natural logarith `Ln` is the logarithm with base e, where e is the Euler number e = Exp (1) = 2.718281828...

#### Conforming to

The function `Ln` is defined in ISO 7185 Pascal; its application to complex values is defined in ISO 10206 Extended Pascal.

#### Example

    program LnDemo;
    var
      z: Complex;
    begin
      z := Cmplx (1, 1);
      z := Ln (z)  { yields Ln (SqRt (2)) + i * Pi / 4 }
                   { since Ln (i * x) = Ln Abs (x) + i * Arg (x) }
    end.

#### See also