HP 3000 Manuals

Compiler Library/XL Reference Manual

DEXP (or DEXP') 

DEXP calculates ex , where x is a longreal number.

Declaration 

        FUNCTION DEXP(VAR x:LONGREAL):LONGREAL; EXTERNAL;

Accuracy 


Attributes 

Parameter:                A representable longreal number in the range
                          [-708.396418532264, 709.782712893384].  See
                          Chapter 1 for details on the internal
                          representation of real numbers.

Result:                   A representable positive longreal number.

HP FORTRAN 77/XL:         Intrinsic function:  Y=DEXP(X).

Error:                    If the argument is a NaN, there are two
                          possible actions.  If the INVALID trap is
                          enabled, the message "DEXP(X): X=NaN" occurs.
                          Otherwise, the INVALID flag is set.  In either
                          case, a quiet NaN is returned.

                          If the argument is >= 709.78271289338397 the
                          message "DEXP(X) OVERFLOW" occurs and the
                          result is infinity.  If the argument is <=
                          -708.39641853226408 the message "DEXP(X)
                          UNDERFLOW" occurs and the result is set to
                          zero.

Special Values 

                 dexp (+Infinity) = +Infinity

                 dexp (-Infinity) = 0

MPE/iX 5.0 Documentation