Procedure

   dpmax_c ( Largest DP number ) 

   SpiceDouble dpmax_c ()

Abstract

   Return the value of the largest (positive) number representable
   in a double precision variable.

Required_Reading

   None.

Keywords

   CONSTANTS

Brief_I/O

   The function returns the value of the largest (positive) number
   that can be represented in a double precision variable.

Detailed_Input

   None.

Detailed_Output

   The function returns the value of the largest (positive) number
   that can be represented in a double precision variable.

   This value varies from machine to machine. The value is defined by
   the macro DBL_MAX from the ANSI standard header file float.h.
   According to the ANSI standard, DBL_MAX must be at least

      1.E+37

Parameters

   None.

Exceptions

   Error free.

Files

   None.

Particulars

   The function always returns a constant value, set by the user
   prior to compilation.

Examples

   The following code fragments illustrate the use of dpmax_c.
   Note in the second example that the smallest negative number
   is not necessarily the negative of the largest positive number.

   1) Set a range variable for a star or ephemeris object.

      /.
      Compute the distance to each object. For stars, use
      a "very large" distance.
      ./

      for ( i = 0;  i < n;  i++ )
      {
         if (  strcmp ( type[i], "star" )  )
         {
            /.
            The object is not a star.
            ./

            range[i] = vnorm_c ( state[i] );
         }
         else
         {
            range[i] = sqrt ( dpmax_c() ) / 2.;
         }
      }



   2) Initialize a CSPICE "window."

      /.
      The window originally has one interval, from "minus
      infinity" to "plus infinity".
      ./

      winsiz    =  2;
      window[0] =  dpmin_c();
      window[1] =  dpmax_c() ;

      scardd_ ( &winsiz, window );

Restrictions

   None.

Literature_References

   None.

Author_and_Institution

   N.J. Bachman        (JPL)
   J. Diaz del Rio     (ODC Space)
   H.A. Neilan         (JPL)
   M.J. Spencer        (JPL)
   W.L. Taber          (JPL)
   I.M. Underwood      (JPL)

Version

   -CSPICE Version 1.1.1, 02-JUN-2021 (JDR)

       Edited the header to comply with NAIF standard.

   -CSPICE Version 1.1.0, 23-JUL-2001 (NJB)

       Removed tab characters from source file.

   -CSPICE Version 1.0.0, 16-OCT-1998 (NJB) (HAN) (MJS) (WLT) (IMU)

Index_Entries

   largest d.p. number