[Overview][Constants][Types][Classes][Procedures and functions][Variables][Index]

Reference for unit 'System' (#rtl)

ln

Calculate logarithm

Declaration

Source position: mathh.inc line 94

function ln(

Ln returns the natural logarithm of the Real parameter X. X must be positive.

An run-time error will occur when X is negative.

Program Example37;

{ Program to demonstrate the Ln function. }

begin
  Writeln (Ln(1));      { Prints 0 }
  Writeln (Ln(Exp(1))); { Prints 1 }
end.

Exp		Exponentiate
Power		Raise float to integer power