Previous: dfloat Up: ../plot79_d.html First: dcosh

DSINH

       DOUBLE PRECISION FUNCTION  DSINH (X)
 C$    (Hyperbolic Sine)
 C$    Return the hyperbolic sine of the DOUBLE PRECISION argument
 C$    X.  The algorithm  uses the host  exponential function  for
 C$    large  abs(X),  with  care   taken  to  prevent   premature
 C$    overflow.  For small abs(x), a 7-term polynomial  expansion
 C$    generating results correct to about 23.89 digits, which  is
 C$    adequate for double precision computation on computers  for
 C$    which there are fewer than 80 bits in the mantissa.
 C$
 C$    The polynomial coefficients are taken from table SINH  1987
 C$    in J.F. Hart et al, "Computer Approximations", R.E. Krieger
 C$    Publishing Co., Malabar, FL, USA (1978).  The ELEFUNT tests
 C$    of W.J. Cody, Jr.  and W. Waite,  "Software Manual for  the
 C$    Elementary Functions", Prentice-Hall, Englewood Cliffs, NJ,
 C$    USA (1980)  have  been  made on  the  DEC-20/60,  with  the
 C$    following results:
 C$
 C$    abs(x) in 0 .. 1/2   - maximum relative error: 1.00 bits lost
 C$                         - RMS relative error:     0.00 bits lost
 C$    abs(x) in 3 .. 88.03 - maximum relative error: 2.61 bits lost
 C$                         - RMS relative error:     0.83 bits lost
 C$    (25-JUN-83)