HP 3000 Manuals

Compiler Library/XL Reference Manual

DTANH (or DTANH') 

DTANH calculates the hyperbolic tangent of a longreal number.

Declaration 

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

Accuracy 


Attributes 

Parameter:                A longreal number.

Result:                   A representable longreal number in the range
                          [0.0, 1.0].  See Chapter 1 for details on the
                          internal representation of longreal numbers.

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

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

MPE/iX 5.0 Documentation