CFLib.org – Common Function Library Project

Description:
Returns the inverse hyberbolic sine of a value. All angles are expressed in radians.

Return Values:
Returns an angle in radians.

Example:

<CFSET x=0.5>
  <CFOUTPUT>
  Given x=0.5<BR>
  The Asinh of #x# is: #Asinh(x)# radians
  </CFOUTPUT>

Parameters:

Full UDF Source:

/**
 * Returns the inverse hyberbolic sine of a value.
 * 
 * @param x      Any real number. 
 * @return Returns an angle in radians. 
 * @author Joel Cox (jlcox@goodyear.com) 
 * @version 1, November 29, 2001 
 */
function Asinh(x)
{
  Var RetVal = 0;
  Var Neg = False;
  if (x EQ 0) {
    RetVal = 0;
  }
  else {
    if (X LT 0) 
          Neg = True;
    x = Abs(x);
    if (x GT 1.0e10)
      RetVal = Log(2) + Log(X);
    else {
      RetVal = x^2;
      RetVal = Log(x + RetVal / (1 + Sqr(1 + RetVal)) + 1);
    }
    if (Neg) 
        RetVal = -RetVal;
  }
  Return(RetVal);
}